Sure thing :)

It is really confusing at first because UDK isnt really that friendly of a program and it's difficult to master. First of all I recommend you to check out

https://www.reddit.com/r/RocketLeagueMods/comments/4wzunj/everything_you_need_to_know_about_rocket_league/

Everything you need to know about Rocket League Mods
In there you can find everything to get you started, you can also check out Wejrox youtube tutorials and some of his videos in which he actually goes through making a complete map:

https://www.youtube.com/channel/UCMi397cEavRXg3eND5fHsgA

And finally, if you have any questions or problems just ask me or post it on the Rocket League Mods subreddit :D

PS: If you dont know anything about 3D modeling just stick to the tools in UDK, I tried learning how to 3D model maps for Rocket League in Blender and, well, it was like my worst nightmare.

Wow thanks man,
Definitely checking it out when i get the time to do so!
He even has whole playlist :o
Im not even googling 3D Modeling, i lost my sanity somewhere at GMod :p