I went to CVW in October this year, you don't need to pack heavy. If your doing the overnight bring a pillow and blanket for your cot, which is what you'll be sleeping in. Bring a change of athletic clothes and a more formal outfit (nothing crazy, for girls maybe nice pants and a blouse, guys khaki pants and a polo). You'll be pretty busy following around your assigned midshipmen, it goes by pretty quickly.
Side note: I personally did not think to do this, but some of the drags brought cookies or snacks with them to give to their Mids. I offered to pay for our doordashed dinner instead lol. They have really busy schedules so just be appreciative of the time they spend with you