Beginner friendly? No.
It's not terribly difficult, but it is more complex.
New Republic would have a lot of your favorites (Han & Chewie, Luke, Leia, Lando, Ackbar, Mon Mothma), but also systems that take some adjusting (limits on # of ground/space commanders, specific political leaders tied to certain research).
Also, New Republic starts with a very spread out, thinly populated territory (concentrate on the Bespin and Mon Cal zones, let the rest be taken as you consolidate), but NR becomes progressively stronger and stronger as most of the others stagnate.
At least one giant ship per faction (NR gets 2), and a much better roster of units.

If you decide it's worth the risk, post and I will give you a more in depth guide for New Republic.

Yeah I would appreciate a more in-depth comment since there are still a lot of things I barely know and I'm not too sure how to approach battles or ship-building. I am still not sure how to even conquer a planet effectively since while I do fine in space I get absolutely steamrolled on the ground

1) Decide if you want to use Boarding Shuttles or not. Using shuttles will require you to adjust how you play space battles, slow down the game, but give you some otherwise unobtainable ships that will either earn you credits, save you credits, or are just entertaining to have.

An important note: in Thrawn's Revenge (and most extensive mods) you cannot safely save during combat (space or ground). I do not begrudge scum saving in a game like this, but each battle is an all or nothing endeavor.

Check out your faction at: https://thrawnsrevenge.fandom.com/wiki/New_Republic

Important notes: 5 types of heroes: Naval(Space) Commanders(4+1), Pilots (all that are available), Army(Ground) Commanders(3), Political Leaders(Only 3 with an actual unit), Jedi(2+1).
Some of these cross over, others have different incarnations for each, all are changed via the second tab on a controlled planet (mission/political). You have to pick which you are adjusting (it is very fast to change, do not pause during this process), and if you are shelving a hero they need to be in orbit on that planet.

Your beginner Naval commanders should be:
Ackbar (only Thrawn himself is better)
Firmus Nantz (still very good)
Sien Sovv (bleh)
Adar Tallon (/sigh ... OK).

First off, change out Sien Sovv for Wilham Burke. You can pick Voon Massa later (or Chel Dorat, but you miss out on a bomber pilot for now), but right now you don't have the credits to upgrade his ship, and his base Lucrehulk is underwhelming.

Assemble one doom stack under Ackbar. Your fleet cap is 300 (sort of) and should be composed of:
1) Tank ship - lots of HP/shields, power to shields or such (Home One, or Bulwark III)
2) DPS ships - long range Turbolasers and Ion cannons, power to weapons (Liberators)
3) Picket Screen - nonTurbo lasers, point defense (4-9 CR90s)
4) Support/Specialty (1xCC-7700 interdictor, 1xBoarding Shuttle if using, 2 tenders if using, and Quasars, Quasars, Quasars)

Use whatever you have to start, but as you can afford to replace them sell off all DP20s (bleh), Nebula B non tenders (they suck pop), MC30 (bleh), Liberty MC80s (awful), MC40a (bleh), Dauntless (pop suck), even MC80b (replace last, it's a decent secondary tank/dmg).
Instead buy up Liberators (5+), Quasars (as many as possible) and CR90s (to fill in pop cap).

Your goal composition as NR is geared around fighter superiority and bombers.
In that regard, ensure Wedge Antilles is assigned to Ackbar/Home One, Ranulf to Nantz, Horton Salm to Burke. As possible, you want to split up some Naval Heroes as Command Tiers do not stack. Fleet 1 will have Ackbar with Burke, fleet 2 led by Nantz with Tallon.

Your beginner Ground commanders should be:
Lando Calrissian, and 2 others
Dismiss anyone but Duron Veertag with his massive Aratech Battle Platform and Tigran Jamiro with his heal bus as these two are central to the NR ground strategy.

Your initial Army strike force should include: Han&Chewie (they do double duty as part of your picket), Duron (battle platform), Tigran (healing), Wedge Antilles (Ackbar must be in orbit). Reinforcements should include (as available) Lando (also assigned to picket in space), MPTL (artillery), T1B (to be replaced later), and Heavy Tracker, T3 or 4B. Don't bother with infantry, starter NR troops suck, and they don't improve much.

Fleet 1 and their army should set out to secure your "Southern" (bottom of galactic map) territory. Start with richer, weaker planets held by Eriadu Authority, heading to the "East". Hyperlanes are the only means to attack, so you can leave planets behind front lines vacant.
Another important component of Fleet/Army 1 is that "small" heroes (Han & Chewie, Lando, Luke, Leia) do not count towards your Fleet pop cap. So you can have 300 worth of ships AND those. How this really helps NR? "Hero of Endor", unlike commander tiers, this buff stacks and you can get it from Han & Chewie (only counts once in space, but twice on the ground), Wedge Antilles, and Lando (Luke has other stuff to do, and Leia doesn't join until later).

You can either land Tigran first (in the scout slot on planetary screen) or Han & Chewie (they operate independently on ground). You want to pause and assess where you can earn free allies (vehicle factory, flight pad, garrison), credits (my favorite), or a battle advantage (repair facility, field tent). Others (satellite, oil rig, etc) are not as vital. Whoever is 1st, land the other 2nd, and hold off on landing others until you have your starters selectable. Start landing Wedge next.
Send Han and Tigran to any targets between you and the enemy base (board Han into Tigran's bus, use the speed boost, when it's used up disembark Han and use his sprint while ordering Tigran to the same destination). Han repairs, Tigran heals, and the two together can hold for quite awhile against any number of infantry, less so vs heavy vehicles, though Han still has his EMP.
If Wedge has landed, send him to harass at a third desirable point or to back up Chewie.
Send Chewie out solo on sprint to start as he can steal a vehicle to protect himself, gain speed, and deny the opposition 1 unit without a fight. Back him up with Wedge as possible, or ...
Last, land Duron as he is your slowest, but most powerful ground unit. Duron, paired with Chewie (or Han) can hold out against nearly anything but an entire army. Neither can repair Duron while embarked, but you can put them on board to lower their "aggro", then bring them back out. The AI tends to attack whatever is closest and attacked them last.

Meanwhile, Fleet 2 and their army ... Luke Skywalker (seriously, he is all you need where you're going) head west into SsiRuuvi territory.
If you are "Boarding" then use Mon Mothma to purchase your Shuttle, and boldly go forth. As usual, take out any non-Ion weapon hardpoints, leaving engines, launch bays, and ion cannons. You should prioritzie Lwhekk tenders, maybe Shree Cruisers. the Lwhekk's have a good healing radius and some fighter trash to mix in with your good fighters. The cruisers are worth more as credits than in combat.
If you are not boarding ... send in Luke. He can stealth past space forces, land, and wipe out every SsiRuuvi planet singlehandedly. This also takes out all space buildings to soften up your 2nd Fleet's work. Your biggest challenge with this method is not overextending your Infrastructure score. So, you want to slow your Jedi roll until you can build in behind him. Paying the infrastructure penalty can gut your expansion. Once the Ssi-Ruuvi are all dead (Luke committed a genocide), send him to Fleet 1 to boost your Hero of Endor stack and give you a little flexibility with the anti-infantry master.

Another important issue in all of this is to leave neutral planets for last as they act as a minor buffer against invasion.

However, back to building ... You want to fill in all your orbitals. Don't bother with trade ports unless the planet has a bonus (if it already has a trade port to start, leave it until you hit cap) or if you're coming up to galactic pop cap. Try building as much as possible with Mon Mothma due to her significant discount. Build tax agencies on your highest earning planets first. Don't bother with tax agencies on anything under 100 credits (it would take 12 cycles minimum for even those to pay off). On planets that make 300+ (without a tax agency) you want to build a tax agency, an infrastructure bldg, and then another tax agency. Influence calculates at the end of a cycle, so don't get cocky and build 2 tax agencies in a row just because influence says it is at 6 now. When possible, build mines first.

AND WHILE YOU'RE DOING ALL OF THIS ...
Consolidate your forces to protect Mon Calamari. You can send the Jedi (Kyle Katarn) to the South to help as a scout as he isn't half the jedi Luke is, and that matters because ...

How the Galactic Empire and Warlords work ...
When you reduce a faction of the GE down to 3 planets and have killed all their "Warlord" tagged heroes they will join up with the most influential (ahem, powerful) faction of the Remnants at the end of that cycle.
Don't let them.
When you are down to 5 or 4 enemy planets, scout them out to find at least one of their leaders and leave that planet for last. This way you wipe them out without giving anything to your opposition. The only downside to this is you may not allow the Empire to advance and open up certain events/planets.

Overall, you want to clear out the South/bottom half of the galactic map until you turn North/up through the Hutt Cartel and finally connect with Mon Calamari. Use Fleet & Army 1 to take out your difficult opposition (Imperial Remnant, Hutts, Hapans, CSA, etc). Fleet & army 2 should take on the Western map (Chiss Ascendancy, Killiks, Empire of the Hand), though you may want to bring in Ackbar and gang to take down Thrawn himself).

All the while, you will receive missions (moreso with Mothma in charge, so keep her as long as you can until you need to swap her out for research purposes).
What you really want, what you really really want is an Aratech Battle Platform. Scumsave as you see fit or not. You will only receive one of these, but then you have Doran's, so that's two. You can either swap him out for another commander (I like Tulon's ATAT with its disposable troops) or make your two armies more comparable (without Han & Chewie your 2nd army will always be/feel incredibly weaker).
After that, there are only three rewards that I consider worth using (vice selling):
#3 Canderous Assault Tank x2, you can buy these yourself once you take Mandalore and raise your influence, but otherwise these are a rather nerfed version of the FOC unit (especially since they deploy singularly), yet still strong enough to be worth using.
#2 Imperial ISD, a decent filler for any fleet.
#1 MAS-2xB Self-Propelled Turbolaser, aka, the Blaster Blimp. This thing flies, tears vehicles to shreds, destroys turbolaser towers and defenses, and even does a decent job vs small targets. It's slow, and its hardpoints do not have much health, but if you can keep it out of reach, it kills anything at long range. Han & Chewie with an Aratech and this can melt entire armies with only a 5 ground pop (yes, the blimp does count as 2 units).

That should cover all the basics.
Good luck, and may the Force be with you (but, Luke ... you really killed them all? Must run in your family or something ...).

The Empire at War Expanded mods are a lot less complicated than often claimed. All the things the mods add (Upkeep, Influence, Unrest, government mechanics, etc) are each very simple in themselves, everything just happens simultaneously all the time. So it can be a bit overwhelming at first. I am a veteran player and still occasionally fall afoul of infrastructure score.

If you already know how to optimize income in the base game, you'll be able to figure things out, especially since all the stats and formulas are listed in-game. The key aspect that filters people is to just be patient, take it slow, read everything, and actually think and do the math before doing anything. If you join the discord server, players like me will be more than happy to explain certain mechanics or give tips, but ultimately you can figure everything out.

However, be aware that the mod is unstable due to custom scripting. Saves can corrupt and ongoing runs can brick due to framework crashes. So save often and never get too attached to any run.

It is very hard to actually lose a GC, since the AI will usually let up if they start to beat you. On the flipside, closing out a GC from a winning position can be a slog too.Remember, it's a single-player game, no one will judge you if you just end GCs once they're no longer fun or if you install sub-mods that make it easier.

All the factions are supremely well balanced, so you can just play what intrigues you and you generally won't be screwed.

you just need to know how to read most confusing things are explained in game

You might want to practice ground combat in skirmish first. Other than that, start with the smaller historical GCs.