Hawaii

I have family who live in Honolulu, so I’ve had the pleasure of visiting more than a few times.

South

Hanauma Bay: snorkeling with lots of fish; make sure you book beforehand and consider buying snorkels rather than renting because it’ll be cheaper
Ala Moana Center: outdoor shopping mall
Kāhala Beach: secluded beach with less people than Waikiki; the Kāhala Hotel has a nice pool and does free dolphin shows
Koko Head Trail: relatively difficult hike with views of the island and Hanauma Bay
Diamond Head Trail: medium hike with views of the city; a bit more touristy than Koko Head
Lulumahu Falls: unofficial trail to hidden waterfall
Manoa Falls: relaxing walk to very tall waterfall

Laniakea Beach: for sea turtles
Dole Plantation: for pineapple-related activities and dole whip (pineapple-flavoured ice cream)

Secret Island: hidden beach with mountainous backdrop (access by walking on narrow strip from Kualoa Regional Park; there’s no need to go with Kualoa Ranch because it’s a public beach)
Kaneohe Sandbar: a strip of exposed sand which takes 30-60 minutes to kayak to (you will need to rent one)
Makapu’u Point Lighthouse Trail: a short hike with cliff views; if you head past the warning signs, you can climb down the rocks to the Makapu’u Point Tide Pools but be careful!

Ono’s Seafood for poke bowls
Liliha Bakery for cream puffs
Fumi’s Kahuku Shrimp for spicy garlic shrimp (I’ve heard Giovanni’s Shrimp Truck is good as well)
Kickin Kajun for cajun seafood
7-Eleven for spam musubi

Get a car.