There are lots of ideas and information on this forum. With or w/o a car, visit the Arizona Memorial first, arriving between 7 and 8 am. Remember, no bags allowed including camera and hand bags. Then maybe wander through Chinatown, do the downtown Palace thing, etc. Then head out to Diamond Head. All can be done easily on TheBus. If using TheBus, continue out and back to Sea Life Park for a scenic ride. If using a car, do the loop around the island leaving nothing in the car you don't want stolen when parking at the North shore (and to a lesser extent at the Memorial). The shrimp trucks would provide a tasty meal.