Don't buy her anything, it'll be awkward.

You're gonna be nervous. Just accept that and try to relax. Tell her you're nervous if you want, it can make it easer.

Avoid negative topics - focus on positive things, have fun. If you self-depreciate, don't do it much.

Try to avoid interview questions (job, siblings, etc). Think of some questions that you're actually interested in - things you can relate to. Talking about things you're passionate about is very attractive. So is listening to her passions. Just don't go on too much if she can't relate to what you're talking about. Funny stories are always good as long as they're not too deviant-like.

When you're comfortable, find reasons to touch her. Compare your hands, read her palm (just make it up and be silly), do a thumb war, stuff like that. If you're walking, maybe softly-bump her so she almost walks into something (personal favourite). She'll probably punch your arm, but that's good. If at ANY point you feel her tense up or physically resist what you're doing (like not let you move her hand or arm or whatever), then back off. Chances are at that point she is not interested.

If she is receptive to your touch, at the end of the night (or when you're feeling good and both smiling at each other), tell her to close her eyes and then give her a little kiss on the lips. If she reciprocates, kiss a little bit more but not more than a few kisses (unless she's actively wanting more). If you're not quite so keen on that, just ask if you can kiss her instead. Maybe she'll say no. At least you had the balls to make a move though. She might say not here, in which case wait until you're somewhere more secluded.