So the SF pasttime isn't baseball or anything like that, it's laughing at tourists who wear shorts. All the visions of warm, beachy California are lies spread by the Los Angeles tv industry. SF can be cold and windy even in summer (actually especially in summer, the land warms up and causes the fog to roll in) and the fog is beautiful but it's FRICKIN COLD. I always bring a jacket to SF no matter what time of year it is. It can be 30 deg C maybe 20 miles away and 10 degrees C in SF. No joke.
SF has awesome food, with a lot of Asian and Mexican influence. Here's a great list from all price ranges: http://www.sfgate.com/food/top100/2014/
Pay particular attention to Mexican/Central and South American food, since I know the UK has great Asian food but not Mexican. The burrito is a Californian staple. Try the al pastor and the carnitas.