No, there is no admission fee for entrance.
Please copy and paste the following link into a web browser to access a map of the Hoyt Arboretum: https://drive.google.com/file/d/1RYuO8nAUgKDCUz96bqbFQ8F0ckfwWzAj/view?usp=drivesdk
See the above link for a map of the grounds. There are two parking lots circled in red that are closest to where the wedding ceremony will be held.
Unfortunately, the closest bathrooms are located by the Visitor Center, approximately 1 mile south of where the Redwood Deck is located. Be sure to use the bathroom prior to the start of the ceremony!
Yes, there are three benches available for use.