When I was but a wee one, I had my adenoids removed. They basically stuck stuff up my throat/nose area and sucked 'em out of there. They put me to sleep with goofy juice (too OP, must nerf) for it and gave me fuzzy socks when it was over. To be honest, it wasn't all that bad. It was terrifying going into it but I didn't feel any pain and I didn't see anything since I was asleep.
I assume you're going to have some sort of thing where you cant walk on it or something after, so while you're immobile just find some games to play or watch some tv/netflix/youtube. I do that since I'm immobile anyways. But that's just cause I'm a lazy noob who hates leaving the house.
Don't sweat it, surgery isn't scary unless it's heart/brain surgery. Read a book after it, play games, do whatever it is you find fun. It'll be coo. All coo.
p.s. You do want this surgery. They wouldn't be doing surgery on you if you didnt need it, and if you need it, you want it.
also your parents will buy you stuff to make you feel better if you're good about it
just saying
if you still don't believe that you need it/want it, I couldn't breathe through my nose until I had my adenoids removed. Think of how pooey that'd be if i never got the surgery. Yeah.