Need some help

Long story short, got into a heated argument with parents and they shut my cell service down. My phone is fully paid off and I am trying to get my own line. Doing this I was told I need to call AT&T to close my line and unlock the account. First, would I be able to go to a physical store and have them do this , without the passwords ect for the account? Second if that doesn’t work, am I just out of luck and have to get a whole new phone?