Hi Angela,
My family just returned from an 8-night stay at Disney's Port Orleans - Riverside and I am certain that you are going to love it there!
I think that booking a character breakfast for your first morning at Walt Disney World is a great idea and something that my family do each and every time that we visit. I'm sure that you will all be up bright and early that day due to excitement!
I would recommend either:-
1/
Ohana's Best Friends Breakfast with Lilo & Stitch at Disney's Polynesian Resort which is a short monorail ride away from the Magic Kingdom.
2/
The Crystal Palace featuring Winnie the Pooh and friends at the Magic Kingdom itself.
As advance dining reservations are highly recommended for all character meals, I would suggest that you make dining reservations for your restaurant of choice at your earliest possible opportunity. Reservations can be made up to 180 days prior to your visit online
HERE or by calling (407) 939-3463.
Wishing you a magical trip!