Yes. If you're staying overnight, you'll have to meet the buses back at the airport. Your documents should tell you where to check in. It's usually in the lobby of the Hyatt in the MCO terminal. There are cast members all over the place on the mornings of cruises, so it shouldn't be hard to find where to go.
Make sure you don't put your cruise tags on your bags until the morning of the cruise, before you go to meet the bus. You'll have to claim your luggage when you arrive the night before the cruise.