Hi Shawn, welcome back to my fellow Ohioan!
On your three-night cruise on the Dream, you'll have a three different attire nights. The first night is Cruise Casual, second night is
Pirate Night, and third night is an optional Dress-Up night.
Disney usually asks that long pants, not shorts be worn in the main dining restaurants. Little boys can sometimes be seen wearing dressier shorts and a polo, but men should wear long pants. Cruise casual is really up to you, but you'll notice the majority of folks will follow this long pants guideline.
On pirate night, bring along some pirate gear, or even a full costume if you really want to have a blast, and enjoy the pirate festivities. All guests will receive a Pirates IN the Caribbean bandana to wear that night as well.
On your final night, you can choose to dress it up even more, which always makes for some nice photos in the atrium before or after dinner! If you choose not to go dressy, cruise casual is fine that night as well.
I hope that helps clear things up, Shawn! Enjoy planning the rest of your fall cruise, and let me know if you have other questions!