Deidre:
First trip to Disney! A flood of memories come back to me of our first family trip.
Although you can certainly spend two days at any Disney park, allowing you to go at a slower pace and not miss any attraction, I would think with the ages of your boys that you'd be able to cover most of the
Magic Kingdom in one day, allowing you to consider heading to
Animal Kingdom, or even
Disney's Hollywood Studios. If your boys are animal lovers, then Animal Kingdom is a good choice for a second park. It will close early enough for you to head back to your resort for an evening swim. If your sons watch the Disney channel and are fans of Pixar movies like The Incredibles or even the Muppet movies, Disney's Hollywood Studios might be a better choice if Fantasmic is playing on the evening of your visit, and especially if your boys like Star Wars, it would be my pick.
Wishing y'all a magical vacation!
Whitney