Sounds like you are thinking about a life boat, not a cruise ship. lol Most cruise ships have between 3000 - 6000 passengers, not counting the crew.
Food is always amazing and they have most everything you can think of. They are also cleaning everything 24/7. Get up at night and you will see them wiping all the hand rails, elevator buttons and door knobs with bleach/water. They do it all day also but you dont notice with all the people.
Ive been on 3, 4, 5, 7 & 9 day cruises, mostly Bahamas and East coast down to Belize.
My best cruise was where I missed the cruise ship in Cozumel and did exactly what they told me was impossible, reaching Belize by land. 1 1/2 days by bus (old school bus) and ran out of money at the Belize boarder. Best trip ever and the captain of the ship came to our room to greet us back on the ship saying we were the 1st to ever make it. lol Everyone knew us on the ship after that also.
Also agree, always get a balcony room. A couple times I got the captains suite because its big and I was on the cruise with a friend/buddy, not a girlfriend or wife.
A little cruise tip/trick I learned my 1st cruise. Dont bother with a wake up call, alarm clock or setting your phone timer. ALWAYS/Every day set out the breakfast room service card on your door knob (dont be shy about what you want for breakfast) and what time. Every morning you are woke up to a knock on the door with all your food on a big tray. Eat in your room or on the deck and yes I do this on morning excursions days too.
The most expensive thing about cruises is the alcohol charge. I dont drink beer so no big deal but I like to have 1 or 2 mixed drinks most days/evenings. I bring a couple bottles of pedialyte or something similar filled with Vodka or Rum and get 1 souvenir drink glass. Juices are free.