Fast attack life = 10 months of the year at sea, (Inport, you'll have duty every 3 days.) Cleaning all the time, Canned/frozen food ALL the time, Cleaning all the time, Sharing a bed with two other guys, Cleaning all the time, Not actually doing any of the cool stuff you thought you would, Having to listen to Officers think they're awesome, and cleaning.
Whatever platform you end up on, just remember, six and out! Your quality of life will be a thousand times better once you're out of the Navy so just suck it up, get the training and experience, then get out and get a real job. As far as studying, basically, you'll have to study since you're ordered to. Plus, if you don't, you'll fail out. Then you'll become a coner, you'll find out what that is. You will have mandatory time to put in every week. It's not hard to make it though if you just try. Good luck with everything.