This is a very broad and wide ranging question. Every service, specialty/MOS, and unit/ship will make this answer vary beyond belief. I went Marine Corps, my room mates all went SWO, my best friend went pilot. Once we all go to the fleet (out of training schools), our lives were so different it is hard to explain. We all amost spoke our own unique languages. USNA2016Dad nailed it describing the intangible of the military. It is a hard life, but it has it high points too. The friendships, memories, pushing yourself, leading, etc are things you will remember. It is like Plebe Year... as you get further away, you forget the bad and embrace the good memories.
As a SWO you will be standing on the deck of your ship 30 days after graduating. Is the ship underway, doing work ups, just returning from deployment, in the yards? This will be a factor in what your daily life is like. What is mentioned above is correct, where do you stand on your quals? Is your ship facing inspection? As a brand new officer quals will consume your life as you try to figure out your job, sailors and shipboard life.
Sub officers go to school for a good bit. After a lengthy training pipeline sub life will vary just like a ship. Every ship or unit has its own personality in the military.
Marines... go to TBS for 6 months, then a MOS school. Those schools vary from 2-6 months if not more. Once you get to the Operating Forces you will be platoon commander learning your job and your Marines. Your days will spent doing alot of paperwork, training your Marines, PT, meetings, counseling, and of course following up and the taskings you have given.
SEAL... lots and lots of school and training then moving on to be a member of a team.
Those are the big ones. As mentioned above a young man called his friends. I would utilize google and you can probably find a lot of websites and forums that talk specifically about this stuff.