Hi, Cassi! It's so exciting to be planning your very first trip as a family to Walt Disney World! I know it can be overwhelming also, but don't worry! There is so much to see and do that you son will love and remember, so you don't have to worry about planning out too much.
My nephew just turned eight, and until Toy Story Mania opened in Disney's Hollywood Studios, he could ride Buzz Lightyear at the Magic Kingdom all day long. Now with Toy Story Mania, we'd have to do a lot of running back and forth! Both attractions are kid and adult friendly, fun, and interactive, and not to be missed on any of our family trips.
Another family favorite is the Festival of the Lion King show at Animal Kingdom. We love the music and the acrobats, and if your son is in any way a fan of the movie, this show is a must see.
If you think a character meal will enhance your trip, my nephews all love Chef Mickey's at the Contemporary, and they've enjoyed Mickey's Backyard BBQ. Your son might also like Donald's Safari Breakfast at Animal Kingdom.
We just saw the new Move It! Shake It! Celebrate It! street party this past weekend, and my kids LOVED it! I'd say that's on the must do list for our next trip!
Think along the lines of your son's favorite shows and characters, and whether he's a thrill ride kid or not, and make your plan based on him. Add in things like the Jedi Training Academy if he's a Star Wars fan, or Captain Jack's Pirate Tutorial if he's into pirates.
Have a wonderful time!