The easiest and most straightforward way is by car. From downtown Berkeley, the venue is about a 15 to 25-minute drive, depending on traffic. Lyft/Uber/Taxi can take you there no problem.
No, wear what you like! It would be good to have a sweater or light jacket for when the sun goes down.
We live in a small apartment and generally have all the items we need. If you wish to give a gift, we've created a honeymoon fund to assist us in taking a memorable trip. :)