It's growing.

If you want it to assume more of a tree form as it grows then do some pruning, at least those two lowest branches.

I'd leave the rest of it for now and just let it grow and become stronger. Then down the road do more pruning to get the look you're after.

Even with pruning at a later date, it is never going to develop into a pleasing or structurally sound tree form. I'd be inclined just to grow it in the more shrubby form it is now. Or replace, if that is not what you want.

I would stake that main center sprout and give it another year before doing any significant pruning. Just stake it enough to keep it upright, yet loose enough to allow some movement in the wind so that the developing trunk is encouraged to strengthen up.

You'll likely get another year or two of this wild growth as the former tree's root mass tries to put all its energy into a limited amount of growth points.