I wanna say this mod isn't particularily straightforward and I am not a authority though I have spent several frustrating hours figuring out how it works. This mod and the mods in the list are what I am playing with so results may vary with that too.

Anyway first off a good source of initial income is gonna come from petrol shops from trucks and the like refuelling. It's not a lot but it should be enough to get you in the green at least some of the time. I say most of the time cause well you are gonna most likely be in the red most of the early game. Mostly because of the industry changes that this mod puts in but ill talk about that later. In regards to the gas station I also wouldn't buy more then say 2 heck even only one is prolly gonna do the job since vehicles don't seem to have to refuel often. In my city of like 60K people maybe one is used ever so often leaving the other 3 of my 4 gas stations constantly empty. It also helps that nobody uses their car since every is always poor (I still have no idea how to affect this as education, land value, health, etc has limited impact on this problem for me)

Industry has changed a lot in this mod and Ill say right off the bat don't expect the industry you control from the industry DLC (not the industry you zone and yeah you prolly need the industry DLC for this mod) to make income for you. The real money comes the choices the "city hall" makes that adjusts taxes and benefits for the people and private companies in your city. Depending on how well your city is doing and what party is currently in charge they will change policies and adjust taxes that will ultimately be your income. They basically act as a counterweight to your success, most of the time if my city is doing really well for money, they will give benefits (Dunno what they are lol I can't find any info on em, all I know is they cost money) and give tax cuts. They also will do the opposite generally when you are in the red too and raise taxes, cut benefits, etc so they aren't all that bad.
Regardless you still need industry cause without it you can't build or maintain anything so I start with one small log yard which supplies the city with the building materials to get started. Btw it seems the more and bigger log yards you have the faster things will get built but the bigger/more you have the higher the cost. Basically what happens is you pay to import the wood to the logging camps, the wood is stored and when a construction happens or a building levels up they take it from the storage area.

I also found that importing stuff is more then likely the best option then to chop the wood especially at the start. Since having all stuff in house means you have less zoned industry which at the early stages means your city is gonna be missing a huge source of income. (trust me you'll need every single cent you get) I guess it may be possible but you are more then likely just making things harder for yourself then it needs to be really. I have also tried but I do not think it's possible to skip putting down the log yards by using industrial specialisations. They either don't produce construction materials at all or very little and I can't tell heck it could be that they drain resources which Ill discuss later. Additionally it appears that only some industry warehouses actually work so log yards will supply your city but sawdust yards will not afaik. It is unclear as even some log yards seemingly decide to do nothing despite there being a need for materials so I need clarification on this too. As they say 0/12 trucks are being used however I do see trucks coming and going to places from the yard sooooooo....There also appears to be a maintenance aspect to this mod too so you will need to increase your storage houses to keep up with demand slowly. Not only that but your industry will need some for their "operational costs" So like they will import stuff from you to then sell to the shops which then sell to the citizens. I don't understand where specialised industry fits into all of this but I kind of assume it is noming resources like the rest of em all the same as regular industry.
Another note is you can also use iron too for the same effect however I suspect it may be cheaper to use wood? Anyway that is what I use for all my runs with this mod thus far.

But yeah as far as the bulk of your income you get that for having more people and businesses. I think the mod is supposed to increase the amount you earn by having citizens have a lotta money but I can't figure out what or how the ♥♥♥♥ to do that lol. If you go into the landvalue info screen the homes in red have little to no money and the more green the homes are the more money they have. Well I can't figure out how that works even when land values/education/employment rate are super high. So I just made do with around 3-4K's worth of poor people to start consistently getting income. You can also get income from these sources too:

Monument-> Resident or Tourist visit
School-> Education Fee
Recycle centre-> Export Production
Garbage-> Outside garbage deal
Toll Station-> Feed through (traffic that bypasses your city via the highways) & tourist traffic
Public transport-> Public transport Fee
Police Station-> Outside Police deal
Hospital-> Outside Hospital deal
Cemetery-> Outside dead deal
FireStation-> Outside fire deal

Some of these require outside connections to be properly configured and installed, I find it hard to actually turn a profit from some of these sources of income like education and health. They more or less offset some of the cost but they more often cost way more then they give in return. Either because my citizens are all poor (millage may vary with what mods you play and how you play it as yeah I still have no idea how to make these a-holes make money and not be poor) and can't afford it in the quantities I need or something else is happening. Either way how I've been able to play this mod is by treating every citizen as if they were disposable at least initially. Not so much that they leave but just enough so I don't have to pay for services I can't operate at the time. Basically you need to be really frugal at the start or you'll have a lotta problems. So just keep building homes and businesses till you start profiting from the taxes you generate from then. Then from there you can try experimenting to see what gets you more income.

To wrap it up this mod for me has been rewarding to slowly figure out but damn it can be frustrating to not know why something aint workin :P