Because I totally got in on the Hawaii deal, looking for recommendations on what to do in Oahu. We’ve got Pearl Harbour and Diamond Head already lined up...

Go to hanauma bay for snorkeling.

Looking for things to do too!

Forget Waikiki- get on the island commuter bus and go to the north shore

Hanauma Bay for snorkeling and the Maita’i Catamaran for a sunset cruise! We are here right now ... so much fun!!

Go to Yokohama bay.. beautiful beach the go to northwest tip and do coastal hike.

Hanauma Bay, and go up north to check out the different beaches. I did a tour where they took you to turtle beach and where they shot the Lost tv series.

I’ve been to Waikiki 4 times in the last 4 years and love it. I really like the convenience and busy/touristy feel (yet you can get out of the busy parts if you go to the north shore). I make sure I do a luau every year. Polynesian cultural center is a nice all day event that most like to do once. I don’t like their luau as much. Chief’s is my favorite luau.

following im going there too 1st week of Dec

Haunama bay but go early

Yes but I believe they are closed one day of the week...so don’t pick that one.

Dukes on Sunday live music 4 to 6

Yes as someone already mentioned, rent a car and drive to the north shore of Oahu. That’s where they hold a lot of surfing competitions.

when are going? There could be seasonal activities.
That said, I think it's worth booking a visit to the Polynesian Cultural Center (there are numerous tour companies and shuttle services to get you there). You'll spend a minimum 4 hours up to a full day depending on the number of activities you take it.
You can do horseback riding at the Kualoa Ranch.
Surfing in Haleiwa on the north shore.
Shallow diving at Hanauma Bay.
If you're into food, stop by Leonards Bakery and try the Malasadas (especially if while theyre warm and fresh).
Stop for a Hawaiian Shave Ice, either at Waiola Store in Honolulu or at Matsumotos in Haleiwa.

ming chin any reasonable accommodation recommendation you know. what about airbnb for one week 3 people first week of Dec any activities during this time? its our first time

Maxx Sorry, haven't done airbnb in hawaii. So don't know which to recommend.
There's a hula show on Kuhio beach on Tues, Thur, and Sat at 6pm.
There will probably be a Pearl Harbor Memorial event on Dec 7.
Every friday night at 745pm there's a free fireworks show on the beach by the Hilton Hawaiian Village.
On the late afternoon of Dec 1st there should be the Honolulu City Lights festival. It's a party with food trucks, parade and xmas light ceremony
https://www.honolulucitylights.org/

I agree with the recommendation for Duke's. It's a Waikiki institution and food is good and not too pricey.

North Shore for sure - Laniakea Beach to see sea turtles, Shark’s Cove for snorkeling, Haleiwa town for cute shops.

Ala Moana waterfall hike was pretty cool, awesome waterfall & lots of bamboo trees

Do not miss Hanauma Bay (closed on Tuesdays). alo do not miss Giovanni’s shrimp truck on the north shore (Waimea Bay beach park is also there)