Hi Heather,
I am with you - if I arrive early enough to head to a park that's exactly what I'm going to do.
No worries - you can go ahead and check-in when you arrive. If your room isn't ready, you can still pick up your
Key to the World Card, leave your luggage with Bell Services and head out. When your room is ready, they can text you with your room number. If you don't use text, they can also call you or give you a number to check in with them. When you arrive back at the resort, your
Key to the World Card should be programmed to work with your room number so you can go straight to your room - all a part of the Disney Magic.
Don't forget that you can do
Online Check-In beginning 10 days prior to your arrival. That will save you even more time when you arrive so that you can get to the Magic Kingdom faster.
Wishing you many magical memories :-) Allison