How do I tell my parents I was asked out?

I'm a senior in high school (17 girl. 18 in the fall) and a guy from work I like asked me out the other day. I said yes, but the thing is that he just turned 20 and this will be my first date ever. I can read people very well and I have turned down dates before from guys that only have one thing in mind. We're going to see a movie late afternoon, I'm driving myself, and everything. I feel like I am responsible enough to date someone out of high school, but don't know how they will handle it since it's my first official date. Plus it will be very awkward haha. So how can I convince them?