The park as a lot to offer for the little ones - especially if they love animals.
Triceratops Spin (Dinoland USA): Very similar to the Dumbo ride at Magic Kingdom with a Dinosaur Theme.
Festival Of The Lion King (Camp Minnie-Mickie): Awesome show based on the Disney film. The music is spectacular.
Kilimanjaro Safari (Africa): An open air truck takes you on a "Safari" into the animal exhibits to see them close up. This is very safe - I first took my younger daughter at 6 months. Tip: take this ride as early as possible in the morning or later in the evening. The animals tend to nap during the heat of day. These times are also the least crowded. It is a popular attraction and wait times can be extremely long toward mid-day. FastPass is available.
Older kids and adults: Animal Kingdom