Be comfortable and dress in layers so that you can take off the sweater or jacket when you're inside. Slacks are accepted in all restaurants . It is a college campus but more than that it is a military post and the cadets work as well as study here. It could even be considered business attire. Slacks or a skirt or a dress with a sweater or a jacket is appropriate for women.
Men can either wear a suit or a sweater or a blazer.
You will meet their mentor and his wife and possibly his family if you go over to their house afterwards. Be comfortable but dressed appropriately. The banquet is full dress for the cadets and the same for guests. Some people wear formals and tuxes. Others wear dressy knee length dresses or a dressy pant suit and the men wear suits.