My friend and I (both single women in our 30s on our first cruise) arrived two days early to spend some time in Honolulu. We took a taxi in, costing $40 with tip. We stayed at the Park Shore hotel, the last one along Kalakaua Avenue right next to the zoo. I booked it through the Entertainment book. Our cityview room was $99/night; the room was very basic (two double beds, a little balcony, a TV, phone, mini-fridge, safe, bath/shower, hair dryer, coffee maker, iron/board) but it was fine. We could see a little slice of the beach from our balcony and they had the nicest smelling shampoos and lotions. The hotel itself had two restaurants, a Japanese one and Lulu's from which there was a fantastic view of the beach and Diamond Head, a pool, a Starbucks and an ABC store. As well, service was impeccable; all requests were happily met and recommendations proved to be excellent.
Speaking of ABC, I'd heard that they could be easily found in Waikiki but I hadn't realized that meant that they were literally on every block; ours had two.
Our first day we went to the International Market, walked down Kalakaua then took in the beach.