沖縄にはたくさんの伝統文化があるって英語でなんて言うの？

The word "indigenous" in general means "something that belongs to a specific place." You can use the word indigenous to talk about plants, animals, cultures, people, practices, foods, and many other things. I hope that this helps :)

When you want to speak about how Okinawa has different traditional groups, then you can say: -Okinawa has different indigenous cultures -Okinawa has many traditional groups

"Okinawa has many traditions. " is saying that there are a lot of traditions in this area (food, celebrations, music, art) "Okinawa has many cultures." is saying that there are many different cultural groups in Okinawa. "Okinawa has many indigenous cultures." Is similar to the above example. It is saying there are many native cultures in Okinawa

When talking about Okinawa, you want to say that Okinawa has many traditional cultures. Of course culture is the ideas and traditions of a race of people, and people in Okinawa may have a slightly different culture to other areas of Japan

"Okinawans have many cultural traditions." says that in Okinawa there are lots of cultural traditions.

"Okinawa has many traditional cultures" and "Okinawa has many historic traditions" These sentences both imply that the Japanese city of 'Okinawa' have many/a lot of traditional and historic cultures. 'Traditional' is the term used for something that is tradition, tradition is the belief or things taught and passed down threw many generations, ex "my families tradition is to name the first son jack". 'cultures' is the arts,beliefs,customs etc from a particular location/destination. ex. "Usually in British culture we enjoy drinking a lot of alcohol on the weekends".