When I was in high school, there was a girl that I had a huge crush on, and she had a huge crush on me, and everyone in the whole school knew it. But we were both extremely shy and never managed to talk to each other. We did hold hands once, and she rested her head on my shoulder, but that's all we ever did.
you know what?just ask her out :p take her somewhere you both would enjoy and start from there. My girlfriend and me were classmates as well and we lost contact for over 15 years till I got her MSN and asked her out. I was pretty much brain dead when we were on our first date,I couldn't even remember most of the stuff I said on that date but I'm sure they were all pretty stupid xD. If you find yourself out of topic or don't know what to say you can always recall your high school memories right? and that's something both of you can talk about :p Good luck dude!