imasrxd saidTake a drive up Tantalus Drive for amazing views of Honolulu from the Round Top Forest Preserve overlook. The drive is really beautiful and the views are the best on the island.
There are fantastic hiking trails at the top of Tantalus. It's been a while since I lived there, but there's a small parking lot at the top surrounded by avocado trees. The trail across the way goes to the very top of the mountain and you can loop back around down the mountain through bamboo groves and other beautiful tropical mountain scenery before returning to your starting place. We always used to take visitors there.
Favorite beaches: Sandy's, Makapu'u, Waimanalo (Belows AFB on the weekends is best), Kailua, Malaekahana, Waimea Bay, Mokuleia, Electric Beach, Makaha Surfing Beach.
There are great valley and ridge hikes everywhere, as I recall there are books with trail guides.
A couple of easyish walks that are fun. Drive to the end of the road past Makaha in Waianae, then walk to tip of Kaena Point. Or on the opposite tip of the island, take the walk to Makapu'u Lighthouse, but just before the lighthouse you'll come to a cliff off the right side of the road, you can climb down it to the tidepools at the water's edge.
Local food, anywhere and everywhere.
PS: Be careful in Hawai'i! Nature is pretty but it is not always gentle. It is not an amusement park. Tourists are forever not paying attention and falling off mountains, drowning in riptides, etc.