East side: The horse back riding is my favorite experience on the island, they also have ziplining or tours which are fun for kids. (Will need reservations ahead of time)
East side: Try Kayaking to the island Mokulua off of Lanikai. (Reservations day before)
East Side: Nice for a gently stroll. Very accessible and beautiful view of the mountains. Free :)
North Shore: Check out cute local north shore bakery, yoga, ceramics, soap factory and coffee making.
North Shore: Try a sample of different alcoholic meads made by honey bees, check out honey and bees wax products.
Townside: Highly Recommend! (Will need reservations ahead of time)
Townside: Beautiful Museum overlooking the Ocean with lots of culture. (Will need reservations ahead of time, tickets release the beginning of previous month and sell out quickly)
Town side: Easy hike and beautiful jungle, non-swimming waterfall. Free :)