Studios have students of all levels, but certain lots of beginners. There are group lessons and privates -- group lessons are common, but don't address particular problems you may be having, so privates are used for that. Of course group lessons cost less, but privates can prove more cost effective in terms of solving a particular problem or learning a particular move. Cost varies, but I'm used to group lessons for $10 to $14 per hour (cost may also vary widely by geographical region, so take that with a grain of salt). Also, I tend towards independent studios instead of chains like Arthur Murray -- too many stories of high-pressure sales in chain studios.
But hey, you say you're in college? Check the PE and Dance departments for social dance classes: ballroom, salsa, swing, etc. Not only will you learn to dance, but you'll also get college credit and take care of some of your general-ed (in my day, PE was required, so ballroom took care of that for two semesters). Or check with student services to see if there's a social dance club on campus; such clubs usually also offer instruction for new dancers, plus they'll have dances where you'll get to put some of that instruction into practice.
And don't be embarassed about being new. We all remember all too well when we were new. When we watch the new people, we're thinking "Hurray! More people to dance with!" and so we want to encourage you and help you learn.
PS
fascination just reminded me about the range of ages in studios. Certainly there are a lot of older people. In particular, I'm noticing a lot of "middle-aged" beginners (my own age demographic) because couples are either finally able to start dancing now that their kids are older and moving out on their own, as well as the singles created by the burgeoning divorce rate around the age of 50 (again, my own demographic). But there are also younger people as well. For example, I tend to see a generally younger crowd in salsa and East Coast Swing/Lindy and an older crowd in ballroom and West Coast Swing, but there is still a wide range of ages in all groups.
If age is a concern of yours, then again social dance resources at school would be worth checking out.