Looking for fun things to do in Honolulu and any recommended tours we should go on?
First of all I highly suggest to buy the Go O'ahu Card. With this card you'll get access to many of the sites, admission to over 30 attractions and a few tours as well.
What do you like to do? Are you an adventure type, then you could climb into a cage and swim with the sharks. O'ahu Shark Dive , rent an ATV at the Kualoa Tours go swimming in the open ocean with the Spinner Dolphins in Waianae with Wild Side Specialty Tours or take the bike ride down the side of a volcano with Oahu Downhill Biking Adventure
Don't forget to visit the Polynesian Cultural Center you can buy discounted tickets here , No evening at the Polynesian Cultural Center would be complete without experiencing "Ha: Breath of Life", you will love this show.
Mahalo! and enjoy the Aloha in Hawaii.
Mentioned in this answer:
I recommend hiking Diamond Head State Monument if you are in fair physical condition. It gets harder at the top, but is worth the view.
It depends what you like! One of my favorites was a tour of Hawaii Volcanoes National Park http://www.hawaiiactivities.com/en/hawaii/big_island/ctg/161921:hawaii_volcanoes_national_park/