It takes a good hour and ten minutes south of the airport to get there depending on traffic. You definitely need a car. There are a few markets - produce along the way where you can stop and get papayas... In Kona there is Walmart, Safeway, and on the way down there is Choicemart. By the airport is Costco. You could do Honaunau or the Tiki village on the way down or snorkel at two step which is by the Tiki village. You pass the coffee shack on the right but it closes at 3.