Please help.

The story is:

I purchased some Sugar Apple seeds from Ebay a while ago. Now some of the seeds are germinated. What should I do next? In order for them to germinate, I put peatmoss + water in small containers. To create a greenhouse-like Env., I put these containers in big plastic bags ( 2 small containers / bag) ,placing under ceilling heater ( 10 fts high) ,next to sliding doors(lead to the backyard)for some indirect light. After 3 wks + couple days, some of them are germinated ( I keep checking the peatmoss to make sure it wet). I am not sure make to do next.

My next question is : how long for these Sugar Apples to bear fruit? If it needs grafting, where should I go ?

Thank you very much in advance