Dating T.T

So I'm off to a date tomorrow, which is terrifying, and I really need some advice. It's not that I haven't been on dates before, it's just that I still got a huge crush on the previous person I dated (who turned me down two months ago). We didn't even date for that long, but I really liked him, so when he told me he didn't feel the same, I felt really miserable. So two weeks ago, to make me come over the previous guy, a friend of mine hooked me up with this guy. We have only chatted with one another, and we're to meet tomorrow. And I am scared I won't be able to shut out the other guy. My date seems so nice, he's smart (studies odontology; study engineering myself) and he is really good looking, and I really want it to work. What to do? How to make it work? Conversation subjects ? Questions? Do's and don'ts? I can't even sleep x.x Head's a total mess :s