I've had some interesting experiences my freshman year. Here are some extremely random pieces of advice:
1.) There are freshmen seminars. TAKE AS MANY AS YOU CAN. Not only are they absolutely fantastic, but they give you extra units! More units = better registration times in the future! I came into UCSD having passed only six AP tests (my high school sucked and only offered six AP classes) but I stacked up on these seminars and within two quarters I have better registration times than lots of my friends.
2.) Should you bike or longboard? Doesn't matter. You could do neither if you wanted. Bikes are a great way of getting around. There are plenty of bike locks around campus and bike theft is pretty uncommon. (However, I did witness four dudes getting arrested last year for trying to steal bikes near the Pangea Parking Structure in ERC. They obviously failed.) Plus you probably already know how to ride a bike.
I originally bought a bike off an older student at the beginning of the year. I rode it for a few months but then I tried my roommate's longboard. I fell in love immediately. I never boarded before so I was pretty terrible (I've had some pretty bad accidents... Image - TinyPic - Free Image Hosting, Photo Sharing & Video Hosting
) However, you get real good real quick if you fall enough. :-p Longboards are definitely more convenient than bikes, plus you can take them on the campus shuttle if you don't feel like pushing up against a fat hill.
3.) Drinking in the dorms is easy and very common. Just be SMART about it. Don't be too loud, don't have too many people in one place, and LOCK THE DAMN DOOR. I've only been written twice... Once because some idiot left the door open to go to the bathroom right and an RA just happened to pass by. (BTW, I didn't get in trouble at all. They just made us pour the drinks out. :-( Poor UV.....) The other time I got written up was because I was racing down a hill on my longboard drunk and shirtless at 4 AM. Don't do that.
4.) My friend doesn't know if it was just his dorm, but drugs were pretty easy to get. He's come across weed, speed (in the form of adderall), shrooms, extasy and even some cocaine. Frats are a big source of the harder drugs. Oh, this is all according to my friend by the way. I don't do drugs and I don't know anyone that does or sells them. Unfortunately my friend fell off Mt Everest and died so I can't ask him any more questions.
What I can tell is to be CAREFUL. Know your limits and if you choose to take drugs, do them in the company of people you like and, MOST IMPORTANTLY, trust!
Weed is pretty safe: you'll just fall asleep or maybe throw up if you smoke too much.
Speed (in the form of adderall) is pretty safe too. However, you do risk cardiovascular damage if you take too much.
BE CAREFUL WITH SHROOMS. Make sure you are in a good mood when you take them and make sure you are not on MAOI type antidepressants - the drug interactions will likely kill you. Also, make sure not to take too much your first time. An ostrich once told me of someone trying to jump out of her fourth story window because she was tripping too hard. Another reason to be with people you trust.
For extasy, just look at the advise i gave for shrooms.
Cocaine is stupid. don't do it.
5.) At the beginning of the year, DON'T STAY LOCKED UP IN YOUR ROOM! GO OUT AND SOCIALIZE. I think UCSD's rep of having a terrible social life is windly overblown but it's not without merit. Please don't perpetuate the stereotype.
I'll add more when I remember.