Eat before you go out, ideally something carby! Take it a drink at a time, your flatmates may well pre drink before you go out, but unless you want to be in bed by 10pm and miss the actual event then just have one drink before you go out. Pace yourself, don't down your drinks or do shots to start, have a drink every so often and learn your limits. You will get used to it after a few nights out haha, and as tempting as it is to go wild and end up chucking up in a nightclub toilet feeling like you are going to keel over- start off slow.