What to expect for a tonsillectomy

I’m getting the surgery done at the end of April and I’m not sure what to expect. A lot of questions I didn’t ask because I had to have a guardian in the room (I’m 17) and I didn’t want her there for those questions. A urinary catheter isn’t used, right? Are plastic retainers for my piercings okay? (I have over 20, and four are fresh and I can’t take them out) if not, can I sign a waiver stating I understand the risks associated with them? Can I wear my underwear for the procedure? Can my boyfriend see me once the surgery is done and I’m in the recovery room? Do I have to take a pregnancy test before the surgery? The answers to these questions aren’t that clear on the internet.