The wedding will be on Whidbey Island. If you are coming from Seattle or from SEATAC airport, you can take the ferry from Mukilteo terminal. You can also drive further north and take the Deception Pass bridge. Here are some helpful websites:

Yes! However, there is no childcare.

No, your attendance is the gift.

Yes, there is a designated parking area for the event.

Semi formal. Keep in mind the wedding will take place in a historic barn and the average temperature is 74 to 57.