Gosh, I love it here! That said, i don’ town horses here anymore. Did my hobby farm down in inland San Diego. But I,ve ridden here at several places, one within a couple miles of the Fremont BART. My SIL rode endurances horses in the hills outside of Berkeley. There are horses all over.
But a hobby farm will not be in reach of mass transit. Mass transit is built in dense population centers, only stands to reason. So you’ll either have to decide to stick w the hobby farm idea and try to negotiate off hours commutes and working from home, or move into the city, live a city lifestyle so you work life is as easy as possible, and commute to boarded horses.
Chickens are allowed in yards in SF, but the goats, burro and horses will need to find other lodging. Housing in the city is very expensive – but it is worth a lot when you are ready to sell, as well. So…
There’so lots of hunter/jumper around here, and dressage both on the peninsula as well as east bay. Eventing at CTETA in Woodside., so various barns cater to those folks. I’ sure north bay also offers many sport interests. I just don’t know them.