Gymnastic questions? Tumbling or trampoline?

I need a way to stay fit and exercise until the next soccer season and because I have recently become intrigued with gymnastics, I want to do tumbling or trampoline (I don't want to do actual gymnastics because I'd be in a little-kids cl plus I'll be quitting in a few months). I'm curious on which I should do. I am 13 and when I was 5-ish I took gymnastics and can still do a cartwheel, roundoff, forward roll and handstand. What will I learn in each? Where (ex: floor, trampoline etc.) will learn them? What skills will I need to get to each level? I will go to the National Gymnastics Training in Aliso Viejo if that helps.