Don't need 跟团.

Mostly there are 4 islands: Oahu, Maui, Kuai, and the big island "Hawaii".

Oahu: well developed. There are tourist agency everywhere in most of the hotels. They offer local tours: little circle-island tour, grand circle-island tour, Diamond Head snorkeling tour, Parasailing, etc. And the shuttle service to-and-from Honolulu airport is only $5.99 / person.

Maui: rent a car and travel for youself. 4-5 days is just enough to play at Maui.
Kuai: same as Maui.

Big island: there are 1-day tour to big-island, and you can book your trip at the hotel over the counter.