This was our first cruise and we had a great, great time! The cabins were spacious and super clean. There were many food options. Our sign & sail cards showed our dining time & table number on them. You have the option to be at the dining hall for the sit-down lunches and dinners on the third floor, or go do-it-yourself at the buffet areas in the Lido deck (deck 9).
All of the staff were very friendly and professional. The room stewards were especially sweet. Despite their hard work they always smiled and said hello when we passed them.
One bit of advice I would suggest is a checklist of items not to forget. We watched many reviews on YouTube, so we brought things that were suggested, like rope to make a clothes line in our balcony, a hanging shoe rack for storage, and a fan for white noise at night. We didn't use any of those items! Yet, what we forgot were the items we needed most: our big Nikon camera, our running shoes for the gym (they don't let you in without them), and my mother even forgot her swimming suit. Also, bring at least two (not one) dress attire for formal dining nights (there are two), and going to shows.
I suggest bringing $500 cash. We used $320 on excursions, and $100 more on souvenirs and stuff on shore at the ports.
There was more than enough to do on the cruise ship in the way of entertainment. The cruise director and assistant cruise director were fun, young guys. They gave lots of presentations over the intercoms and TVs in the cabins of things to do and shows to see. There were group dances, ice carving, cocktail classes, lots of classes on many other topics like exercise (belly flattening, etc.), towel animal making, etc.
Carnival is all about good safe fun and it shows. The culture the entire time was one of unpretentious fun and relaxation.
Oh, and they have a kids-free zone called the Serenity Deck, and I tried it one morning to read a book I brought on-board and guess what? It's just below the miniature kiddie golf course, so there was plenty of noise there, unfortunately. Also, while I'm complaining, they have too, too many zones on the ship that allow smoking, especially the 5th deck where the casino is, as well as the 10th or 11th aft deck, and as a result I smelled way more secondhand smoke than I would have wanted to.
Overall, it was a wonderful cruise, however, and we already have booked our next cruise!