So does my pony you really just need to spend a lot of time with him on the ground so he trusts you. It took a while but my pony trusts me a lot more now and it's easier to get her to do what I want exspecaly at shows
You should do some pole work, and after a while raising them a little higher. If he seems confident just make a small course of ground poles.
Start small you don't want to give him something to big to start that will only probably make him more anxious make sure his is comfortable jumping small jumps like poles or cross rails before you move on
You can try lunging over a jump or raised pole, that's what I do with my boy to get him used to the feeling of leaving the ground
I'd say do a lot of pole work first and then introduce a raised trotting pole before starting into little cross poles. It might help to have it at the edge of the arena to begin with, our 3 year old found it harder to jump in the centre! A ground pole or guide pole might help him judge too. As long as you're confident and show him you're not worried, he'll be ok!