Can a 17 year old girl move in with her 18 year old boyfriend in N.J but she lives in Puerto Rico. What are the charges for her boyfriend if they get caught and will she have to go back to P.R.?

The girlfriend's charges: she will be charged with illegal Immigration at the very least. The boyfriend's charges will be assisting a felony, underage housing of an nonpaying guest (probably), using technical marriage allowances without actually being married, and absolutely with illegal transport of supplies (assuming you move her stuff into the apartment as well).