Skip wikiki (sp)…it’s a big city with a small beach.
Must do: Pearl Harbor - arrive early in the morning & allow half a day or more. In addition to the memorial, there is a battleship, a sub and several museums which are worth while seeing.
Diamond Head- it’s one heck of a hike but the view is worth it. TAKE several bottles of water (hydrate, hydrate, hydrate!) and I recommend a flash light as there is a dark tunnel.
Get a shave ice. Hit the local supermakets - it’s an eye opening experience. There are deflib machines at the beer isle for folks like WALL and Boss. Buy at your BEvERages at Sam’s club if you can.
Be mindful of what’s in your car. There are signs everywhere including Diamond Head about not keeping anything in your car. Face it, the scum know you’ve got good, easily stolen items and chances are you aren’t coming back to press charges.