Hi AP,
The Magic Kingdom is filled with so many attractions that are family-friendly for all ages. To help highlight many of these, the
Magical Beginnings Guide is for parents of pre-school aged children that showcases many of the attractions that children 5 and under may enjoy (just an fyi that ToonTown is currently closed).
I also think another way of looking at the must-sees for younger children are the attractions that have no height restrictions. If you look at the
Attractions at Walt Disney World (click on the attached link) then select the
Magic Kingdom and then
Height and check
Any Height, you'll get a list of possible attractions. However, there are three you'd want to think about with younger children:
The Hall of Presidents since it may not hold your children's attention and
The Haunted Mansion and
The Pirates of the Caribbean since they may be scary for some guests.
I'd encourage you to visit Fantasyland first, park your stroller, and then enjoy all the attractions there. You may also want to include a character meal at
The Crystal Palace or
Cinderella's Royal Table during your day as well; characters come to you rather than standing in line to see them.
Thank you for the question; please let us know if we can help again.