Hey Vixen!
First of all, someone who drinks to the point that he/she doesn't remember has a drinking problem. Even if it was the first time or just one time, the signs are there...it means that person cannot control him/herself. Like you said, reconsider who you hang out with.
You might get stuck taking care of your friend each time you go out....oooh, what fun!
Second; I would tell him that he had said some nasty things that you didn't appreciate (no need to go any further) and let him know that you are worried about his drinking. I would also let him know that next time he would do that would also be your last time with him.
Other than that, welcome to the drunk's world! Did you just turn 21?
You can go out, drink, and have fun, but there is no need to over-do it. You would just feel like poo the next morning