Everything lol!
Grab a horse carriage ride, drinks around the world, desserts around the monorail, park hop like crazy, or grab a bench and a cup of coffee and people watch.., take s ride in the balloon at disney springs, stay at a different resort and do what you want.. instead of what the kids would want.
Enjoy... whatever you decide.
Once you do it, you ll be hooked. It’s a total different experience enjoying adults only disney.