I'm too scared to get my first boyfriend?

I'm 17 years old and I've never had a boyfriend. I'm a very reserved person so this doesn't bother me, I actually really enjoy being single! But when people do ask me out I get nervous and reject them. Mainly because the commitment scares me and I don't know how to be a good girlfriend. Plus I have very low self esteem sometimes and I'm afraid this will scare the guy off. I'm also in my final year of school and I'm going to University next year.

Anyway, last night I went to my friends (they're twins) 18th birthday party and I met this guy who is a mutual friend but he doesn't go to the same school as the rest of us. This is one of the first guys I've met that I've really liked. It started off when I made a bet and I said I'd buy him a drink if he won. He did so I bought him a drink and he bought me one later on. When I've had a drink, the low self esteem vanishes and I feel so much better about myself. We hung out and talked for the rest of the night and we swapped numbers (nothing happened).

I have a feeling he'll ask me out but I'm so inexperienced in this that I'm afraid, even though I really like him. I don't want it to distract me from my schoolwork etc.

Help!!??