You'll love the ship. No dead end hallways. Midship elevators. A much bigger adults only area. Make sure to visit the Cove Cafe. It's in the adults area at the front of the ship. A nice quiet place to get a cup of coffee and a snack.
While the Grand Theatre on the Wish is pretty, the atriums on the Dream and Fantasy are stunning. And open.
Can't remember the shows on the Fantasy, but make sure to see as many as you can. They are Broadway quality.
Oh, and download the Navigator app. Everything will be on it...your dining rotation, any tastings, on board or port adventures you've purchased, movies & show times, etc. If you're sailing with someone, you can set up the "chat" feature through the app.
I always buy the Internet package, too.
You'll love Castaway Cay. Lots to explore on the island. Climb up to the top of the tower and you'll see everything.
Oh, and Pirate's Night. Bring pirates gear...people do dress up. If it's a Halloween on the High Seas cruise, make sure to catch the lighting of the tree. And people wear costumes.
You'll have fun. There's so much to do. My cruise later this month is my 16th. There are still things I haven't done.