Jumping a horse for the first time - tips, tricks and safety per cautions?

This week I am learning to jump a horse for the first time. My friend who is very well experienced and is in charge at the barn I am riding at reccommended this black pony for me to jump with because he takes them seriously. But a friend of mine who boards the pony in the winter knows all about him and says that he wont listen to me if i ride him and he will take the jump quick and exit the jump quick. Now, my friend who works at the barn said i should still use him because she says hes a good fit. I am working on trusting her decision to put me on him. Now, I am 17, a bit nervous to jump him because of what I have heard about him, but i was wondering mostly what to do if I feel that I am going to fall or if he bucks. Do I slide off? My friend is gonna teach me two-point and everything and the jump isnt too high. I trust her .. I dont think ill get hurt I just wanna know whats the best way to avoid getting hurt while jumping and even cantering. Just horse safety in general. Im just nervous!! I Know that for horseback riding you need to be confident. and i am working on it ...

sorry this is so long .. all answers help, please take it seriously. thank you!!!!