Janice welcome to our world
One thing I never cruise withour is a power strip for all the electronics,and a garbage bag to serve as a hamper in the closet,and also, maybe an over the closet plastic shoe bag, for all the things you need at hand, jewelry, sail and sign card, snacks or whatever.
Are you going to Nassau on this itinerary? If, so walking off the ship and booking at the pier is very easy. If by chance there is something exceptional you want to do,and you want to know you have it booked, tand comfortable with the price, then go for it. Ships tours are more $$.
Remember if you are flying to the port..airline baggage restrictions make overpacking just a memory
Hope your first is a blast, and, you book onboard for your next one