Glad you are reading and asking questions--keep doing that. By the way, there is a teen ostomy forum on www.uoaa.org website. Here's the link for the forums http://www.uoaa.org/forum/index.php you'll find a general discussion page like ours here and a teen discussion page. might be helpful?
In regard to pain, in most hospitals, almost every doctor, nurse, resident will ask you to rate your pain on a scale of 1 to 10. This will help them gauge how you're feeling and assist in getting you the right amount of pain meds. Asking questions and keeping track of how you feel is a good idea. You might consider bringing a notebook so you can write down any questions or concerns for your doc or any advice your doc or nurses give you.
Remember this is all about
YOU feel and hurt--you are the most important. Don't worry about
what your mom or anyone else thinks.
As for me, my brother and husband tell me I was in a lot of pain when I woke up but I don't remember it at all. When I came home, I was in more pain than in the hospital and had to work on getting the right combination of painkillers. Really, it turned out ok.
I think you're being incredibly brave and am impressed that you are gathering information!