Eat all the In-N-Out you can while you're still in California
When I first came here from LA, the hardest part was carving out my niche. I tried to do things that I would have been interested in doing in California, but it turned out that the different setting brought out very different tastes for me. It's amazing how the kinds of things that are available to you on a regular basis have so much control over your preferences. Have a drink at a nearby bar one night, or check out a dance club. See a play, or read a book in the park. Learn how to rollerblade/swing dance/rock-climb. Try as many new things out as you can in the beginning; you'll probably discover that the activities and habits you finally settle into are quite different from those that were comfortable when you lived in SF.
Good luck finding an apartment!