Can you leave the dorms at night? Do you have to sleep in your dorm every night? How regulated is this?

You are able to leave your dorms at whatever time you choose, as long as the campus is not on lockdown (does not happen often). You do not have to sleep in your dorm every night, you can choose where you sleep. You are a grown adult in college, no one is micromanaging you while you are at RPI.

I am an international student. This is my first time in America. Can you explain what is proper professor-student interaction in America? How do American students address their professors? How should the underclassmen treat the upperclassmen? Any more advice about American society would be so helpful! Thank you!!

Advice on all of American society could not fit within the scope of this single answer or even this whole website. What I can say is that in any institution of higher learning, there is a certain amount of respect expected from everyone generally. It’s small things like addressing a professor by “Professor (blank)” or not calling out in class, etc. It’s basic common sense. The upperclassmen are also a great resource on campus, so do not hesitate in asking for help or getting to know someone. You’ll just notice these things as you spend more time at RPI.

I am planning to buy stuff like clothes, towels, toothpaste, and school supplies when I move to RPI’s campus. Do students living on campus get discounts (from RPI’s bookstore, Walmart, etc.) for the stuff they need to buy for their rooms?

There will be “back-to-school” sales at places like Wal-Mart and probably the RPI Bookstore, but it won’t be just for students buying stuff for their rooms. It will be public sales/discounts, not a student discount.

Are you allowed to go to the dining hall and take food to-go? For instance, am I allowed to go there, eat, and put more food in a lunch box and take it with me?

Short answer: no. You can take simple things like pieces of fruit and food that you’ve already eaten part of. There are also meals to go which allow you to get food at the entrance to take to with you. Imagine how difficult it would be to make money if people were coming to stock up on food once a day and taking multiple meals with them.