It would help if you post type of boat and position. Reason, I can’t tell you about crew boats or anchor boats. I can tell you about the mudd boats.
I hope the Master puts you with someone good as your safety partner 1st. 2nd you being in the military, thanks for serving by the way, you should have more self motivation then most folks. This makes advancing easier in the civilian world then the military. (It’s up to you, not what someone thinks of you.)
All posted good things but it will be up to the Master on a lot of your questions. Some may let you do laundry while on watch some may not. Some may let you watch TV during hours during the night some may not. Do what you feel is right also, to many times I was told to take a break while working, during your work hours. You will soon find who are the slugs and don’t follow there footsteps. Enough about all that, you will find out.
Bring a Kindle if you have one, if not and like to read then go to the pawn shop and by one. Folks on the boat will have 1,000’s of book you can download on it. A laptop is recommended also if you like to play games or watch movies. Also get a smartphone if you have nobody to pay your bills while gone. Speaking of phones …STAY OFF THAT DANG THING WHILE ON WATCH. It will get you into more trouble then you know. Again some masters may allow it, some not during daylight hours and some not at all.
1st hitch just bring you something to occupy you while you are off watch and find out what the rules are from the master.
Just saw on your other post you are a wiper. You will most likely need at least a weeks of cloths, you only bring 3 days worth and the washer goes down not only will you feel miserable wearing dirty cloths your shipmates will not want to eat around you. LOL! The deepsink ain’t a good place to wash cloths clean.