High Jump?

I run distances for my high school. My coach decided that he wants to put me in high jump. I practiced for it i get over the bar and stuff but i dont think im good. do u have any advice|||This is my first year trying high jump and my coach told me to just remember to use your arms and get a good arch with your back. Also to practice running up to the bar and getting your footing correct.|||suck your butt in!!