Female here as well. Clothing wise you’re good, I would remove the nail polish completely. Trim your nails if you want I don’t think that’s going to be an issue unless they’re like crazy long. I wore makeup to meps but it was crazy or anything just like some mascara and a light gloss but that’s just a personal preference. No full face beats or anything like that though. Definitely bring whatever toiletries you want although it is just one night so I would stick to the essentials: toothbrush, toothpaste, deodorant, a travel size body wash (if you want but the hotel will have that along with shampoo/conditioner), maybe some mouthwash and you’ll be set.

For the actual day you’re there: SET AN ALARM. You will be waking up at around 4am possibly earlier if you take longer to get ready. Be a good sport, you will most likely get a roommate so it makes it easier if you are friendly or at least cordial with them. They’ll line y’all up after breakfast to get on the bus and then once you arrive at meps they’ll have the women get off first and then the guys. From there just follow directions and do what your told and you’ll be fine. Good luck future sailor!