Jeremy, I don't see you having a career in concessions at a movie house.  But money is money and if you look at it just as a transitional job you are doing only for the money, then you may slog your way through.   Of course it will never satisfy you, but if you are worried about keeping it for a while for the money, make friends with the co-workers and ask how they do it is my advice.

One piece of advice I got when trying to figure out what to do is that it's easier to find a job while employed. So if you hate it, keep looking for another job.

Also ask for some training, never hurts.

Well, I was in your situation when I was your age.  People were on average 10 years younger than I was.  It'll be a good test for you on how well you could adapt to your environment under all sort of situation (you'd be surprised how important this skill is).  Try to mix into your crowd, and learn their subcultures.  If you poses as less age-conscious, maybe they'll see you as one of them.  Being around younger people makes you feel young also, and you get to see the younger generation in first-hand experience, rather than what you heard about them via the unreliable media (what do those people know about young people?).  You also get to learn a lot from young people, and new ways of doing many things.  And another perk in a job like this is, you get promoted much faster than they are.  We all are trying to adapt to the world we're in.  If you really can't stand it after a month, well, it's not a job you'd sacrifice a lot if you quit....