O'ahu for First Timers
Day 1: Arrival + Waikiki
Aloha! Welcome to Hawaii. You'll likely arrive mid-day and stay in Waikiki. After you get settled at your hotel, take a look at iconic Waikiki beach and take a stroll over for lunch at Marukame Udon (there's a line but it moves fast).
Shake out the jet lag and get your blood pumping with a walk up Diamond Head and enjoy the great views of the ocean and city--it's a decent hike and cool to walk through the old bunker. The 99 steps up the last part are tough!
Take your pick of 2 local eats for a snack--Spam Musubi or Malasada's at Leonard's (donuts, but they're not just for breakfast!).
Walk around Waikiki, people watch on the beach, and if you're feeling adventurous, go for an outrigger ride or surf lesson. End with a great dinner--try one of the many great Asian restaurants Momosan/Morimoto Asia, Jinroku Pacific, Chibo, Tonkatsu Ginza Barin, or Roy's. Something lighter? Go for local seafood or a poke bowl at Ono or Meguro brothers.