First off, if you haven't kissed her, don't kiss her in front of a bunch of other people. It's just weird and awkward, especially since you don't know what you're doing yet. So find a place that is relatively quiet and won't have people staring at you.
You can do one or two things after you've found your spot. One way to do is by warming up to her. Flirt and talk with her, set the mood to a more flirty or romantic one. Start caressing her arm or leg or hair and as you talk, slowly inch towards her. Then wait for her to look at you in the eye when you're up close. Wait for a second, close your eyes, and go for it! If she refuses to look you in the eye, gently start caressing the under side of her cheek and slowly guide it towards you and kiss her. That is the more slow and romantic and cheesy way. The other way is to do it quick and simple. When she's looking at you, quickly lean forward and do it. It'll catch her by surprise at first. But if she liked it, she'll either can't look at you and get into a fit of giggles, ask you to do it again, or will kiss you herself.
To determine which one to do, the cheesy one or the quick one, is up to you. It's your call on how you want to set the mood. A more flirty mood calls for the cheesy one. A more friendly mood but still slightly flirty calls for the quick one. I've done both to guys before and guys have done both to me. So yeah, it just depends on the mood of the situation.
But if she is not responsive in any way, whether she is being cold to you or not flirting back, then don't kiss her that day. It'll just ruin your first kiss with her and no one wants that. Although a lot of first kisses tend to not be the perfect one, they are often still enjoyable and thrilling. But kissing her when she's not in the mood will make your first kiss less than enjoyable or thrilling, so be sure to be considerate of her feelings.
Anyway, I wish you good luck!