Hi Heath,
Only being able to spend one day at the Magic Kingdom is still getting to spend one day in Disney - I'd take it!!!
Your question got cut off, but I'm assuming you want to know if you can visit any restaurant, or if you're limited to those restaurants inside the Magic Kingdom and at your chosen resort. You can visit ANY restaurant on Walt Disney World property that accepts the dining plan. Some of the best restaurants are located in the deluxe resorts. You can click
HERE to find a list of participating locations. If you're looking for suggestions Jiko at Animal Kingdom Lodge and California Grill at the Contemporary Resort are two of my favorite places to dine.
The only restaurants you wouldn't be able to dine at that are on the list would be those at other parks: Hollywood Studios, Epcot, or Animal Kingdom. You would need to have a park hopper pass to gain entry into these parks before you could dine there.
Hope this helps. Have a magical day!