I moved here to New York with my boyfriend and our 12 month old son so he can be closer to his family. But all my family lives in Florida. We live at his parent house, I don't have anyone up here. And has recently left me and kicked me out. Can I move back to Florida with our son? He threatens to arrest me if I cross state lines. But I have no help up here. I just want to go back home, but I don't want to leave without my baby

i moved here to new york with my boyfriend and our 12 month old son so he can be closer to his family. but all my family lives in florida. we live at his parent house, i dont have anyone up here. and has recently left me and kicked me out. can i move back to florida with our son? he threatens to arrest me if i cross state lines. but i have no help up here. i just wanna go back home, but i dont wanna leave without my baby

The "boyfriend" is the father of your baby, right? If so, both of you share all custodial rights, until specified otherwise in a court order.
He can't have you arrested because you wouldn't be committing a crime unless you hid the child from him.

At present, either of you can petition the court to set specific custody and child support. How long have you been in New York? It matters, because jurisdiction to establish custody depends on the answer. If the child has been in New York for at least six months, jurisdiction would be there, otherwise in Florida.

Yes how long have you lived in NY is one question, and of course they could not just "kick you out" they would have to actually do eviction process ( but that is another question)

You do risk, esp if NY has jurisdiction that they would order you to move back with child to allow father rights to visit. But at this time you can move if you want to