I would suggest trying out a few different instructors. Each of the instructors at my gym is different. Some I like better than others. I can usually tell the ones that are spin/aerobics instructors and the ones that ride outside. I generally prefer the latter but being a roadie doesn't necessarily make someone a good instructor. As others have mentioned, you don't have to do something just because an instructor is telling you to. If it hurts or just isn't your thing, skip it.
I actually like spinning because I can get into a really intense zone. It's a fabulolous workout. If, however, you don't like loud music or the group dynamic, then it may not be your thing, no matter the instructor.
Live with intention. Walk to the edge. Listen hard. Practice wellness. Play with abandon. Laugh. Choose with no regret. Continue to learn. Appreciate your friends. Do what you love. Live as if this is all there is.
--Mary Anne Radmacher