Dorm rules are mostly common sense. If you’re under 21, no alcohol, obviously. RPI doesn’t allow parties in dorms, but that’s not really an issue since there’s usually something going on off-campus.
As far as room decor goes, none of the multi-colored 5-arm lamps since New York State considers those a fire hazard, the same goes for any upwards-facing lamp. RPI doesn’t allow anything that resembles Christmas lights, as unfortunate as that is. Curtains and flags are also on the no list because of the state. They should have sent you a list of things you can and can’t have at some point, if not, let me know and I can go scare it up.
The guest policy is also pretty reasonable, you can have guests over for 2 nights at a time, but of course, make sure your roommate is fine with it as well.
Quiet hours are from 11 PM to 7 AM on school nights and from 12 AM until 9 AM on weekend. Other than that it basically comes down to common sense and common courtesy. If you’re thinking of doing something that you think might be against the rules or might disturb someone else, don’t do it.