A day in the life of a soldier (can't speak for squids) starts around 5 a.m. Zulu, first comes morning formation (gathering at your unit HQ for roll), followed by breakfast, then morning P.T., usually followed by several hours at your job (whatever M.O.S. you have), followed by lunch, then another few hours on the job, evening P.T., then dinner, then evening formation, and finally rack. So not too different from a 9-5, except for the formation, P.T., and deployments. I was a tanker who didn't actually get to complete training, so my schedule was a bit more severe. Training units are harsh, tightly packed activities, lots of screaming, weapons drills, more screaming, punishment P.T. (doesn't matter if you do everything perfectly, Drill Sergeants exist to break you in any way they can then build you to where the military needs you to be), it is not a pleasant experience honestly, most soldiers go through 9 weeks of B.C.T., tankers go through 16 weeks of O.S.U.T. (I made it halfway before my knees had accrued too much damage to continue), the Navy is it's own beast obviously, but every single seaman I've spoken to says that it's around the same amount of stress and physicality (I knew several soldiers who had decided to switch from Navy to army, and have met several others who decided to switch from Army to Navy, with very consistent assertions from both sides.)
I will not lie, if you join as enlisted it will be the single hardest thing you have ever done, but once you're in, the benefits are huge, and it can be an absolute blast.
As for the additional rank on entry, it's not really a big deal unless you're talking about starting at Captain (only a lieutenant for the squids) most people aren't going to bitch.