If you like snorkeling, go to Hanauma Bay on the south side of the island when thr park opens. You can see fish swimming around when the water is at knee level. Pancakes at Boots & Kimo if you are near Kailuah Beach on the eastern side of the island. Lots of great places including Pearl Harbor which is a must. As others will tell you try to avoid Waikiki as much as possible.