Don't get drunk at parties. You go to parties to meet guys, enjoy conversation, and show yourself off. You can't do any of these when you are falling down drunk. And, guys go to parties to pick up girls. They know that falling down drunk girls will likely not object to getting laid.
And know your limits. Tolerance for alcohol is a learned thing, If you haven't done much drinking, a couple of drinks can get you into trouble. Best plan is stick to beer, from a bottle. You can drink enough to quench your thirst without getting smashed, unlike say martinis.
Same goes for weed. Couple of tokes is probably OK, but a whole joint can put you on cloud 9 if you aren't experienced with the stuff.
Have a plan for getting home from the party. Don't depend upon friends, they may hook up with a really cool guy and disappear. Walking alone after dark is a bad idea. If you get to your car and find you are too buzzed to drive safely, just take a nap in the car.
If you really want to get pie eyed, do it on dorm, or at home, with some good same sex friends.