So many things, we don't even know where to start. Even if you have been to SF already, you can't go wrong with Twin Peaks Hiking Trail for gorgeous morning views, Pier 39 for delicious calamari and clam chowder, Ferry Building Marketplace or Haze Street for shopping, or Baker Beach for an lovely afternoon.
A wonderful spot with lots of fine shops, markets, and restaurants. A good place for lunch if exploring Berkeley, as it is near UC Berkeley Campus and University Avenue.