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.