Where can I practice Parkour In Pomona CA?

I really want to do parkour. I already know.most of the basics like a cheetah jump, kong vault, roll, I'm working on run up wall backflip and frontflip, I tried a gainer but I go hurt badly......so anyways anyone wanna do parkour with me I'm still kinda new I'm 14 and I want to do parkour so badly. does anyone know a place with mats trampolines stuff like that