I just started on this fourm so here is my first request of the experts.  What should I cut?

Last year I rooted the top cutting from my one tree.  In the attached picture you will see the short bush (clay pot) resulting from the cuttings.  I did not pinch because the growth was in the later summer.

The bottom and middle sprouting branches are on opposite sides of the main stem and would form a nice shape.  The top sprout juts out on the 90 degree angle giving the tree a "bent" main trunk.

Given it is just May, should i cut back to the second branch right now?

Im no expert first off but i will chime in on what i would do if it were my tree only.

I would first put in bigger pot its final size and point the bend towards the sun.
I would take out anything growing at soil level if you want tree shape instead of bush shape.

As season marches on those upper branches i cut at the end of branch after i see 5 or 6 pairs of leaves.
You will soon get more shoots around the cut area and more starting at nodes along the branch itself at a few nodes usually close to the cut.
This is time to be picky and select a nice strong straight outward growing shoot or 2 for next seasons new fruiting branch growing off this seasons branch and let grow and repeat process next season.
Keep cutting off  most other shoots that sprout to keep tree in check.

Keep original branches for a few seasons until you get the hang of it and watch how it responds when trimming and you will learn how to prune tree as good as anyone.

Eventually you can cut off that branch close as possible to where your new selected fruiting branch is growing.
Its something that i do each season to my trees unless i go for growth such as total height which i do prune a little different when very young.
Again im no expert i just go by what works for me .
Hope this gives you some idea's.

martin - thank you

Martin, I would like to see before and after pictures of what your pruning looks like. If you have some pictures could you post them for us?