Hi there, thanks so much for asking the Moms Panel! I'm Angelo and Magic Kingdom is my favorite park!
Your question all depends on the type of tickets that you have or are buying. If you have the Park Hopper option, then yes, you can come and go to and from ANY of the four main parks (Magic Kingdom, Epcot, Hollywood Studios, and Animal Kingdom) whenever you choose.
If you do not have the Park Hopper option then you are limited to the park which you are attending for that day. That doesn't mean that you cannot leave and return though.
There are many dinning options at the resorts as well. We ate at California Grill in the Contemporary Resort a few weeks ago, the food was fantastic and the views of the Magic Kingdom are amazing! There is also 'Ohana at the Polynesian, Whispering Canyon at Wilderness Lodge, and if you are looking for really unique experience Victoria and Albert's at the Grand Floridian is fantastic! All of these resorts are easily accessible from the Magic Kingdom park. If you want more information about Walt Disney World Dinning, call (407) WDW-DINE or follow this link to the Walt Disney World
website.
I hope you have a Magical Time and if you have any other questions please feel free to ask!