The Kaneohe Sandbar is a popular place for families because it’s an easy Oahu swimming spot. Kids ages 2 and younger are free and it’s fun for kids of all ages.
Kids as young as 2 years old can participate. And they can feed/pet the horse after their ride. This is one of the best things to do in Oahu with toddlers and preschoolers.
The most popular attraction on Oahu is Pearl Harbor. While it’s not really geared for little kids, it's still an awesome place to visit to learn more about its history.