awww, don't worry! You'll be fine!
The most they'll do is take a picture of you smiling, take a mold of your teeth and put spacers in. The spacers aren't all that fun, but it's not that bad. It was worse for me when they first put the braces on, because I also have a VERY sensitive mouth and my gums were like D= "ZOMG! WHAT'S THIS MEDAL THING THEY PUT THERE?! WHAAAAA!"
And it does hurt a little bit when they take them off. They say "Ok, now you'll just feel a little pressure." but....it like a lot more than that. D=
Nothing realy ever MAJOR HURTS tho- it's just uncomfortable. The only thing that ever really hurt was after they tightened them, and then I couldn't even bite a TINY M&M without it hurting. That wasn't fun. ;____;