How long does it take to be on pointe?

I started Ballet when i was 4,on and off ,mostly on till i was 12. I don't dance anymore but i do moves at home and still stay extremely flexible. I am now about to be 16 and I want to get back into ballet just to be on point because that's all I ever wanted to be do. I just need to get back into a little better shape. Any suggestions on what to do?