aww, this sounds so cute, and yeah, theres a load of dos and donts. Too many here to list, so I'll give you my advice. Get her a seperate drink, instead of you two sharing one. This is just a cozying night together and not an official first date, so no sharing a drink until you have been out together for a few weeks or so.
The first kiss? Well, don't rush into it and dont plough straight for the lips at the first opportunity you get. You will know, when its the right time to go for the kiss, but make it slow, make it special and make it the right moment, otherwise, BOOM, the night is ruined and she'll feel fed up and pissed off with you.
Use your initiative and think what she wants, as well as what you both want, and yeah, the night will go swimmingly.