California and the Bay Area in particular has pretty much always been the best place in the U.S., and one of the best places in the world, for cycling. If you're not riding a bike regularly you're really missing out.
Davis is traditionally far better than the Bay. Better infrastructure earlier, and much flatter.
Davis is one city I thought? SF/Daly City are the only places with unavoidable hills in my experience.
Always carry a patch kit. Puncturevine is everywhere. I got so tired of fixing flats that I bought kevlar-lined tires, installed kevlar armor under that, and used pre-slimed innertubes. The added rolling resistance on a heavy steel-framed Miyata was a workout, but flats went to zero. It's the bike I also used at UC Davis.