Hello Autumn,
Thanks for writing! My home is filled with photos memorializing some of the magical memories we made at Walt Disney World when my boys were your son's age. You will surely have an incredible time. In my opinion, each of the Walt Disney World Parks has a unique and incredible number of
attractions and experiences for little ones. If you have four or more days, I recommend trying to visit each of them. If you have a shorter time frame, I would recommend starting at Magic Kingdom and then adding, Epcot, Disney's Animal Kingdom and Disney's Hollywood Studios in that order.
At Magic Kingdom, some toddler favorites include: Dumbo the Flying Elephant, "it's a small world," Mad Tea Party, Peter Pan's Flight, The Many Aventures of Winnie the Pooh and The Magic Carpets of Aladdin.
At Epcot, my picks for little ones include: ImageWorks - "The What If Labs," Journey into Imagination with Figment, The Seas With Nemo and Friends and Turtle Talk With Crush.
At Disney's Animal Kingdom, I would be sure to include: TriceraTop Spin, Kilimanjaro Safari and Affection Section.
At Disney's Hollywood Studios, I recommend: Muppet Vision 3D,
Disney Junior Live on Stage and Forever: A Frozen Sing Along Celebration.
As you can see, all of the parks are loaded with wonderful options for your tiny tot! Have a magical trip Autumn!