Some things to remember when you jump are: look where you are going, Remember energy, don't worry! You'd rather canter out then trot out so squeeze! Lastly, have fun! Jumping will grow on you! Its really fun advancing too! I love jumping (I jump 2'9) :) Have a good lesson
If you are having a lesson couldn't you ask your trainer this? Sorry, but I agree with above posters, jumping is a no-no if you don't know how. You should be fully knowledgeable in two point, releases, etc before you progress over small crossrails and the occasional small verticle.