The Oakland Museum of California (OMCA) is at 1000 Oak St, Oakland, CA 94607 with the main entry off of Oak Street. The museum is a multi-level building with a grand stair down to the garden area where the wedding will be was well as elevator access to all levels. We recommend taking BART to Lake Merritt Station, which is ~1.5 blocks away, or taking a ride-share or taxi to the venue. Parking is available at the museum as well but is limited and the garage will close at the conclusion of the wedding. Multiple bus lines converge near the venue as well which is also an option. We recommend checking out the museum itself on your visit. There are great galleries on Art, History, and Natural Sciences of the state of California, and the multi-tiered outdoor garden space is free to access. There are also interesting rotating special exhibits as well.
Yes, see the Travel page for more information on accommodations.