Hi again Jenna,
Walking from the Transportation & Ticket Center to Disney's Contemporary Resort is not possible.
In all honesty, because you want to make an Advance Dining Reservation so early, I think that the Best Friends Breakfast featuring Lilo & Stitch at
'Ohana or
Kona Café at
Disney's Polynesian Village Resort are your only real options.
If you make an Advance Dining Reservation at either of these restaurants for an early breakfast, you will be able to park your car at the Transportation & Ticket Center and take a short walk (approximately 5 minutes) over to Disney's Polynesian Village Resort.
Then, once you have enjoyed your breakfast, you will have the option of taking either the resort monorail or boat across to the Magic Kingdom park for the rest of the day.
The only alternative would be to make an Advance Dining Reservation at a restaurant located at Disney's Grand Floridian Resort & Spa or Disney's Contemporary Resort, drive directly there and then move your car to the Transportation & Ticket Center after your breakfast, before making your way to the Magic Kingdom park.
Wishing you a magical holiday filled with memories which will last a lifetime!
Emma