Tough to think about. Being single and ideally relatively mobile I'd guess you'd be good to cover at least 10 miles a day which would be significant in the bay area considering the hills nearby. You'd just need to know where to go. Which, the big locations these days will be schools, especially high schools. It's a good idea to know the location of your nearest city hall and high school. From there the goal will be to collect information, list your options, and rank them.
I've lived through some emergencies near you (rural north bay) and I would recommend turning on and listening to the FM & AM radio in emergencies. FM can get you stations at some distance, and there's a reasonable chance some of your local transmitters will still be up, or will be brought back up quickly. Local is fantastic for getting news that's relevant to you, at least hourly in my experience.
But in the case of national/international news, AM can also help in that it can get you (especially in mornings and evenings) plenty of news stations from in and outside of California if your area is devastated. I picked up a TX/MX border station in the middle of my house one morning a couple years ago for example.
If you have a shortwave radio like the PL-380 or CC Skywave, it will additionally be easy to pick up some stations like Radio New Zealand here in CA in the mornings and evenings. But be sure to practice this before the emergency.
If you worry about making contact from your position, it could help to pick up an FRS radio like the Midland XT511. That way you could monitor for people on the radio and call out if needed, especially if cell towers are down. When I went through that kind of emergency up here, ham radio and FRS still worked fine, and in fact the WIN system was up and running so I was able to talk to people in Ireland, Hawaii, etc.
At least in the 1990s SF had plenty of prominent targets, from what I read in books at the time. One of them (I don't remember where I read this) was the Chevron oil refinery & storage facility just off the Richmond bridge. Driving past all those oil tanks you can kind of see why. Hopefully it was just some fictive thinking though...
I was also just reading a book about a POW doctor from the UK who was right in Nagasaki when the A-bomb went off there. Shortly thereafter, aboard an allied medical ship he was...probed...and announced good to go / clear of long-term effect afterward, which surprised me. The book is "A Doctor's War", pretty interesting overall.