How long do you think to go on pointe?

If you have a really good teacher around 3 years. If not, it may be less than that. Yes, I did say less not more. You really need strong ballet technique along with a strong body and that takes time, There is no shortcut to that. Often recreational dance teachers put their students up too soon due to either the pressure of losing the student to another school, or due to not knowing better because of the training they came from. When you go en pointe, the transition should be seamless. If you cannot do it on flat, you wont be able to do it en pointe.