(1) Don't be that annoying guy/gal. Most classes will have "that one annoying guy/gal". Not really the person who sits in the front of class, but that person who is so needy that he/she won't shut up. Enthusiastic people in class is great. Needy people however are the worst - and you'll find quite a number in school who are neurotic control freaks who worry about the most immaterial things - and it's these people that end up being the ones asking the really annoying questions and making the most asinine comments in class.
(2) Be patient. In the first 2 months in your first year, everyone is insecure to some extent. We all want to make friends. You will make friends. You just have to be patient. You don't need to go to every single social event possible. Be yourself, stay reasonably active but not psycho active, and you will find like minded souls.
(3) Don't be the "life of the party" in the hopes you think it will last. Some people really really hard to be the "man on campus". They will try really really hard to organize all the parties, social events, and will amp their persona/personality to an artificial 11. And people WILL gravitate to that person in the beginning because it's better than being alone. But once people start becoming friends, they will abandon that "man on campus".
(4) Avoid jargon. People who speak in too much jargon sound like tools. And your classmates will play buzzword bingo behind your back. If you are that buzzword guy, no one is laughing with you, they are laughing at you.
(5) If you ever get cold called in class and you are caught off guard and don't know what to say, just respond "me no speak Engrish, MBA school making mistake."
(6) Expect people to gossip about you. Everyone seems to gossip about everyone else. Can't avoid it. News travels fast, even if it only "allegedly" happened.