Be gutsy in your approach
At the end of the day, it's not your graduation year but your quick wit that will win her over. Set yourself apart from the other guys your age (and hers) who are gawking at her from a distance, waiting until they've had a few more beers before they attempt to kick it by making a straightforward, confident approach.
A self-assured stance from your first interaction will ensure her you can handle yourself for the night in question and beyond. Because truly, our worst fear is a trembling boy who is awkward and unsure of himself. We're terrified of being blindly manhandled in the dark by a guy who thinks a clitoris is a tool used by anthropologists.
Assure us you know how to handle yourself from the first words out of your mouth, and if you're lucky, we might bank on the chance you'll be able to handle yourself elsewhere.