I went in November. First you sit through an admissions briefing, then your cadet will come pick you up. From then on, your pretty much do what your cadet is doing. Go to their classes, their extracurricular activities. You do everything with either your cadet or one of their buddies. I got to go to an extra class or two by going to my cadet's roommate's classes with her, and I got to go to two different club sports practices that way too.
Advice, wear khaki's and a polo shirt or nicer, bring athletic clothing and sneakers in case you get to do a sport, take whatever opportunities you are offered, and ask lots of questions. I had a blast.