I would e-mail the head of the music department, if you have already thoroughly read the department's web site and cannot find what you are looking for. As far as where/how to practice, Dixon Hall has practice rooms and I assume you sign up, with music majors getting preference. At least that is how it works at most schools. There used to be some practice rooms in the old student center, but those went away when they rebuilt it as Laverne-Bernick. There might be some rooms in odd places around campus, but Dixon is the hub of the music program.