ur dad is the primary account holder right now, if you want him to keep paying ur bills then u have to stay under his name
if u make ur own account u have to be at least 18 and go to the store for it (unless they have an option to do this over the phone or online)
best thing to do:
pick a phone u like
ask dad to buy it
ask dad to pay for ur service
get new phone
activate
profit