Like lordroad said, join some clubs. *
List out your intrests, join clubs that correspond to those. *This way, you'll meet people sharing at least an intrest with you - a nice start.
If you want a pretty easy way to meet people (and you're willing to stretch yourself a bit):
A ballroom dance club is *always* tilted in ratio. *There are ALWAYS more girls than guys in these clubs (generally speaking). *I'm in one right now and there are ALWAYS girls without partners. *Even if you're a total klutz, join a beginner's class. *You can't tell me you'll get an easier chance to meet someone and (if you can manage) dance and talk with them for a bit at the same time.
*Generally not a lot of guys do the classical dance thing and it's (generally) looked upon favourably. *Don't worry about being terrible at it. *Relax, have fun, follow instructions and you'll be fine.
There have been several "common" complaints though (from girls):
Don't:
- use the death grip
- push/pull forcefully
- step on toes if you can help it (accidents are understandable)
Do:
- be polite
- follow instructions
- have a sense of personal hygene
P.S. Don't be too discouraged. I'm 20 myself and I didn't meet my girlfriend until I was 19. Don't worry, if you're sincere and considerate, you'll meet someone. Guaranteed, the nice guys won't finish last.