What is it that you are confused about? Please ask
Here is a simple way around it.your first decision should be what motor do you want to run, that will eliminate two or three classes.
Then decide if you want to run foam or rubber
And finally plug in the car you want to use!
Gp2 will be the biggest class and it is the same rules that are used across the nation for the most part .
Maybe I am biased but it does not seem confusing to me, really.Pick your class ,build the car and race at a faaaaaast track