For reference, Navy boot camp typically has a duration of 8 weeks (can be slightly shorter if you're a push division or not, or longer if you're held back for various other reasons). There are a few special programs (such as SEALS) that have a MUCH longer duration, however after boot camp they are sent to their respective A-schools or sea school for those without a rate and striking out. At this time, they're able to have internet, phone, and general life privileges again (provided they aren't in trouble for other reasons). There are many forms of "Restriction" that go in place if you've violated the UCMJ (Uniform Code of Military Justice), however the longest they are legally allowed to impose without a Courts-Martial is 90 days while simultaneously cutting your pay.
From what I hear now, people are allowed to bring their phones and smoke during Boot Camp, however this was not the case when I was in. They're also going through a "sensitizing" program for RDC's (Recruit Division Commanders - think Drill Sergeants for the Navy) as there was a large attrition rate due to extreme physical and mental punishment. One of the more famous ones during my time was called an "Ice Cream Social," where the RDC's would place a large tub of ice cream in the middle of the division's barracks and you would do push ups or other strenuous physical activity until the ice cream was completely melted. Not a fun time. For those that chose to hydrate (drink water from their canteen) during this time, they would stop PT'ing (Physical Training) with the group, the RDC's would grab a chair, and sit them down while they drank water until they puked, while his bunk mate would do push ups in front of him to demoralize recruits from thinking of themselves first instead of the whole division.
The Navy is all about Honor, Courage, and Commitment being the "core values," and Integrity is a big hot topic, especially for my rate. If someone was to "blaze logs" (write down false information or information they could have in no way retrieved sitting on their ass and not looking at a gauge) we could potentially lose our "keys" to the reactor (there aren't actually keys, it's a metaphorical term for being able to operate the nuclear reactor) and be stuck in Port for months to re-train. This puts our ship on standby and forces us to not be mission-ready (as we can't leave without our power source not existing), and loses out on valuable training for new sailors that needed sea time and specific qualifications for their rate. There's no way to train someone how to steer and depth management while sitting next to a dock. It's also incredibly difficult to do torpedo evasions and other similar drills while you're AFK in base. Although drills suck ass (I won't deny that, I hated breathing through a mask for hours on end - or worse, sleeping in one if there's toxic gas in a sealed submarine) they're incredibly vital to League in a similar fashion to grinding up the ladder and getting the knowledge you need to successfully climb and be a better shipmate (teammate - also, don't call a submariner shipmate unless you want him to hate you, we use it as a mostly satiric term to "shipmate" others and act like Chiefs). Also, you can't hear the shrimp making love sitting in port - they are too far away from the coast.
For League, ELO Boosting is the equivalent of having one of your good buddies that's a higher rank sign off on your qualifications when there is no way possible that you have the knowledge. If I signed off someone for, say, Main Steam, they damn sure better be able to draw the system and know any spec I ask them, or it will come back to bite me in the ass later. Maybe not today or tomorrow, and maybe nobody will catch that it was me who passed him through, but if there's a Steam Line Rupture and they have no idea how to isolate it, we're all literally going to die (we're probably dead from a large SLR anyways, however knowledge is power) and it's going to be me that killed the entire crew for letting them stand a watch that I knew they weren't prepared to take. It's a similar fashion in League, if Baron is up and someone is pushing bot without Teleport while their whole team is grouped top, be prepared for a LOT of missing pings and reports for boosting, as it becomes obvious. That's why we drilled in the Navy, to prevent those situations from happening. When someone shuts down a Turbine Generator and loses the entire Port (left) side of the Engine Room for a Starboard (right) issue, they're going to be yelled at and have a bad time. It endangers the whole crew at that point, and now we have compounding problems and have to decide which is the lesser of two evils to fix first. Are we going to die from loss of Hydraulics and sink to the bottom of the ocean or are we going to lose all cooling to the reactor and have it literally melt through the bottom of the boat? That's not a fun position to be in. Similar situations (although less dire) arise within League.
I wish you the best of luck in your career, OP. I hope you picked a rate that you enjoy and get to see all the places you want - remember that your location that you're stationed is entirely determined by the "Needs Of The Navy" clause, however the higher you score on tests and your position/GPA in class will give you more lee-way in where you go. E1-E3 is generally a freebie and will be given to you after a certain amount of time, however you'll be able to take tests after that which will provide you with ranks (and subsequently, more money). The higher you score, the more likely you are to get promoted. As you rise up in rank, the tests become less about your specific rate's functions and more about "general military/Murica" knowledge. You're in charge of your own destiny. Knowledge literally pays in the military. If you have the time, you can pick up a second language (not Spanish) and use that to give you more money - translators for Russian and Korean are always in hot demand, and will give you a nice stipend for just existing. Make the most out of it while you can, keep your nose clean, and use your benefits. Make sure to utilize your GI Bill - I'd recommend using it when you're out as the Navy will often pay for your education while you're in, and you can bank on the GI Bill later (either Post 9/11 or Montgomery GI Bill if you paid into it) to supplement your living expenses as well as go to school on the government's dime.
Also (not sure if you're decided yet or not) I wouldn't recommend Submarines if you aren't comfortable with other dude's grabbing your junk all day - that's how we say "hi" to one another - and hot racking (sharing 2 beds with 3 dudes - one guy gets up and the other hops in while the bed's still warm, hence the term "hot" racking). Be prepared for some extra fun non-sexual harassment (most of us aren't gay, we just like grabbing other men's junk, it's part of our culture, but if you're gay and down for it enjoy, there's no discrimination between rate, rank, culture, race, or anything on a submarine - every man [and women nowadays on a few select ballistic missile subs] is valuable and treated equally), as well as not having ANY internet, phone, TV, or other basic amenities for months at a time, as none of them are available underwater. Also, be prepared to run out of food, as there's only so much we can stock at one time. I'll never forget the day when our choices for a meal were "Brown gravy with rice or yellow gravy with rice. Oh and we're out of rice. We have peanut butter and jelly but we're out of bread." With that being said, you'll find very few bonds like the submarine force, everyone knows each other on a first name basis as there's only just over 100 of us, compared to the 5000+ you'll find on aircraft carriers (CVN's). All of us hang out together when we're off, it doesn't matter if you're a fresh E1 or the LCPO E6, you're going to drink (unless you're underage, then don't say anything about it :x) with us and get to know us, everyone is valuable. Even the Officers hang out with us filthy enlisted. I try to treat everyone in League the same, the love between humans is something really special and should be fostered, in my opinion. When you rely on someone for life and they rely on you, it becomes a very emotional place when someone leaves.
Also, thank you for your service! :)
Source: I was a Nuclear Machinist's Mate onboard Submarines - MMN2 (SS)