Hi Leilani, and welcome aboard! I bet you're getting excited for your very first cruise with Disney!
There are a few different themed nights that you can expect onboard, including a formal night on your seven-night sailing. Though schedules are always subject to change, you can expect four cruise casual nights, one formal night, a semi-formal night and Disney Cruise Line's most popular night, Pirate Night.
On formal night, we have seen everything from a simple summer-type dress and men with button down shirts to women in evening gowns and men in tuxedos. Semi-formal night is similar. Our family really enjoys getting dressed up for formal night though, as we don't get many opportunities at home to do that, and it certainly makes for nice family photos. You will see many other families dressed in their best that evening.
Pirate Night is a favorite of our family. If you have pirate outfits or accessories, be sure to pack them, as you'll have fun taking part in all the pirate events and the deck party that evening. If you don't have your own pirate gear, there is plenty of pirate merchandise available to purchase on the ship.
Have fun with the rest of your cruise planning, and I hope you enjoy your first sailing with Disney!