Business casual is always appropriate but not required. Just be presentable, it is more like a lecture than a meet and greet. You will do that later in your application process.. Your MOC's will mostly have 0ne of these, sometimes one for each MOC or mostly a group thing for all do to logistics with the coordinators from each MOC present. DoDmerb is the place to ask questions. They usually have a good representative there to answer question and give some good information if you have any questions regarding medical with some contact information. They sometimes have representatives of the Merchant Marine (both Academy and Maritime Academy's with commission options), ROTC and even OCS sometimes. A parent should go it is very informative. Good Luck.