If you're looking to explore the island a bit more before or after the wedding, the town of Coupeville is a great option! There are lots of cute shops and they filmed part of the move Practical Magic there, so there are lots of halloween-y events there in October.
A scenic, historic, and ecologically significant area featuring high coastal bluffs and beaches.
Fun collection of shops, highlight of which is a pie store.
Beautiful state park with great views, tidepools, and a short hiking trails.