Advice regarding Okinawa trip in last week September

Hi, I'm traveling to Okinawa from 27 Sept to 2 October. I was wondering what would be an ideal duration to spend on the trip given I won't go snorkeling or diving. I'm planning on having a relaxing vacation and sightseeing.

Can you suggest some 'dont miss out' places?

I would love to visit some islands nearby if possible as well.

FYI I don't have a driver's license so will have to rely on public transport.

by runawayfeline