Hi , I wanna planning my daughter's 1st Bd in Brace Canyon park I wanna know for renting jumper and taking to the park should I ask permission from city or ....or maybe it doesn't need?

Yes for renting of park facilities you will definitely need to call the park and recreation department 818-238-5330

Depends on the size of your party. Living there for over 20 years I've learned that if you keep the occasion confined to a couple of benches, there should be no complications. However it never hurts to inquire with Parks & Rec for their recommendation.