Okay need socialiozing help?

Okay in roughly one hour i am heading to my university pub for a halloween party/ karaoke party. I havent made any real friends on campus as of yet but plenty of people know of me. Also a girl i had a brief.... encounter with that ended and we are now extremely awkward around each other is going. I have a jack bauer form 24 costume and i am in the proccess of drinking about a cup of vodka for liquid courage. Advice for a successful night is appreciated, please be specific