What the bad little cadets in the YouTube video are doing is a little forbidden something called "Rodeo Buffing". Why is it forbidden? As you can tell from the video, cadets can get hurt, but more often something around the buffer, or the buffer itself breaks, causing tax payers more pain. I would not recommend making Rodeo Buffing a normal past time.
Each year what you do changes...as does the extent that you can get away from "The Factory".
Your first year is generally going to be packed, and you will not have much liberty. My recommendation, sign up for a sponsor family during Swab Summer, and take advantage of their house every chance you get. My Sponsor Family was great and I would just go over there on the weekends to relax.
The next year you have a different liberty policy.
Your junior year, again, you will have more liberty, civvies, and more of a reason to head up to Boston, or down to New York. Newport RI is a destination, but don't get caught there in civvies unless it's authorized.
Finally your senior year you will have the first taste of "freedom" or atleast what feels like freedom compared to what you've been used to the past three years. You'll have a car, so use it. Go up to Vermont or NH and ski. Don't forget to pick up those underclass shipmates of yours who still don't have a car or a steady and easy to use transportation system. You're liberty will feel good, almost like you're a normal person until you realize the true freedom of college campus from your civilian friends.
You have to make your own fun while you're at the Academy. That may come in the form of Spirit Missions, finding a fun sport or intercompany (IC) activity. There are plenty of things to entertain your time and plenty of shoal water on the way to getting that diploma, so keep your head on straight, know the end goal (the fleet and serving your country), and remember to stay honest with yourself and your shipmates.
My class started out with over 300, I think we graduated...206. Getting in isn't the trying part, staying in is.
Good luck! Hope this helped a bit.