Alright so I met a girl, I'm from the US, she's from the UK. I have a GED, no job, but very capable of getting one (my parents decided to cover the price for me, they'd like me to relax and visit family as much as possible before I'm off), and previous work experience. No criminal history. I plan on taking some form of college course or getting work, but I'm really focused on just getting there for now. I'm going to live with the girl and her mother, planning to eventually get married. I understand the passport bit, but I don't even know what a visa is or where to get it, or what kind I'm eligible for, the same with citizenship.
If you would've asked me 2 years ago if I ever thought I'd be leaving America, let alone my state, I'd probably have laughed, so I've obviously never looked into this before. Any help or a point in the right direction would be immensely appreciated.