I second the Polynesian Culture Center.
Also, unless it’s a non-commercial event or party that you are invited to and is being put on by a native Hawaiian family, stay away from anything called a “Luau.” Commercial ones at hotels or on Waikiki are overpriced tourist traps - basically mediocre Hawaiian-style banquet food with some dancing on the side. The dancing (and for that matter the food) is a lot better at the PCC.