Waialae/Kahala Beach is just past Diamond Head a couple of miles east of Waikiki.
The spot we use is up the beach about a 200 yards from the parking. If you have mobility challenged people, look at Waimanalo or Magic Island.
We perform ceremonies either on the sand or on one of the grass spots under the shade of the coconut trees.
Ceremony times at 9 am or 10 am are best. It's cooler, good for photos, less busy, and parking is generally available. After 10 am, parking is tough, use our transportation, taxi, Uber, or Lyft. If not, arrive at least 30 minutes earlier than we schedule to wait for parking.
FYI: Any wedding company agrees to a ceremony after 11 am with more than a single carload, is doing you a disservice unless, you have a single large vehicle transport for everyone.