You can bring lamps, TV's, stereos, computers, some light furniture, and microwaves and mini-refrigerators. You can bring posters, pictures, anything really. You can bring candles, but you may not burn them, and their wick must not be blackened. If you have any questions, feel free to ask a staff member. They have been and probably still are where you are.
Some friction is likely.
Very rarely are their no problems whatsoever between roommates. After all, you are living with a new person whom you don't know well. As for that, give it two weeks. Most problems can be solved and habits gotten used to in that amount of time. However, if you still have problems after the first two weeks, contact your Hall Coordinator or the Department Director, and they will see what they can do to rectify the problem.