All you need to do is go to Rainbow Grocery on 13th and Folsom. Be prepared to spend two hours in there, because they have everything! And food that will propbably agree with your stomach, as it is all organic and healthy.
Let me give you an early welcome! I live in S. San Fransisco. You'll love it here. Beware of some weirdos downtown, and bring a purse (if you're a girl) that can go across your body, and not be pulled from your arm. It's a lot of fun here!