You have experience traveling. That’s a major hurdle. You know your air plans, hotels and dates. Check - you’ve covered so much already, along with the cruise.
Make sure you have a current passport (not required for cruising to Bahamas, just a good backup if an emergency flight home unregrettably happens). If not, be sure to have a state-issued birth certificate and photo ID for each of you,
You can (and most veteran cruisers do) skip a port excursion in Nassau. Check out options if want to visit the water park at Atlantis resort or take a boat over to Blue Lagoon for a beach day or dolphin experience or go to Pearl Island. A lot if us just stay in the boat. It is an easy port to walk from the ship and walk around a bit and see the town for themselves. You might find some aspect you love. Margaritaville is walking distance and offers a day pass to its beach front and smaller water feature area.
Castaway Cay offers some boat-based excursions. Give the excursion list a look over and see if there’s something that interests you. The island is only for Disney, offers a relaxed environment with free loungers and shade umbrellas. An adequate lunch is offered (In both family and adult areas). There are beaches available to everyone and then an adults-only beach, Serenity Bay. You can ride trams to your destination after a short walk. Souvenir shops and bars are available on the island.
The ship provides towels for both the island and for use at the ship’s pools and spa.
I firmly believe a first time cruiser can go and do nothing extra on a short cruise and be satisfied. Show up with some clothes - don’t forget bathing suit, sun hat, and sunscreen - and you are pretty good to go. That was my experience.
You will have an assigned restaurant and table each night. You will not miss out experiencing any menu if you just eat in the MDRs (Main Dining Rooms). There are extra-charge Adult-only restaurants onboard. First time guests have difficulty pre-booking but might be successful once on the ship. Brunches are more likely to be full. My family skips Pirate night in the MDR, as we aren’t fans of the menu (other people love it).
Three nights, there will be a production show in the main theatre. (The 4th night is a variety- type act). Two show times, coordinated to go with the two dinner seating times. (Designed that no one misses them because of scheduling.) No reservations / tickets necessary.
Throughout the day, you can choose to do nothing or attend a scheduled activity. What, where and when for your particular cruise will be discovered by you (on the app you put on your cruise) each evening for the next day. No scheduling fast passes / virtual queues or lightning lanes).
Nighttime activity for adults is from about 10/10:30 - midnight, maybe 1 am. It’s tame. The ship is basically asleep from midnight (or earlier until morning).
I am not a (edit: party) person and have happily fallen into a pattern when cruising. On a non-port day, I have three meals, play Adult trivia (because I am very weak in Disney knowledge that is often the focus of all-age games). Enjoy the ship, walk around, see the evening show and see a movie - either in the nice Buena Vista Theater (current theater movies from Disney Co) or late night outside on the jumbotron (Funnelvision) - these are more PG-13 releases from recent years. Maleficient 2, Jungle Cruise, Cruella, Captain Marvel, for example. It’s not busy, but it is relaxing.
Often adults will sunbathe, get coffee from Cove Cafe, read books, chat with fellow guests, go to the spa for treatments or use the free gym, enjoy drinks from the various bars, participate in the free activities (typically 30-45 minutes per session). And meeting Disney characters. Unlike WDW, it Is not designed for you to schedule, pre-book, or fill your day with activities - or standing in lines.
Pools are notoriously small on cruise ships. Often full of people standing in the water; it just depends on time of day.
I find the website, Disneycruiselineblog, to be very helpful with information. For example, you can see the menus for the restaurants here:
https://disneycruiselineblog.com/menus/
Have a great cruise!
Ask us for more specifics if you want.
