First, I'd run to my friend Mike's room. He is the resident zombie-killing expert. I think he knows some people who have a veritable bunker, with guns and food and all that jazz. If we made it, and they let us in, we'd probably chill there for awhile.
If for some reason we were forced out of the bunker, I'd get myself a mountain bike, some water and food, a baseball bat/crowbar/similar bludgeoning instrument, perhaps a gun, and a partner or two with the same equipment. Then I'd make my way out to I-5 and head south into the mountains. I'd always camp in the top, where I had either sheer cliffs (up or down) or open fields on either side. I'd have someone keep watch while the other slept. The remote location would probably cut down on the zombie encounters, and the open area would give us a good view. If we spotted any approaching zombies, we'd hop on the bikes and just cruise down the mountainside and up the next. When we figured we'd gotten far enough away from the undead menace, we'd stop again at the top of the next mountain.
Eventually I'd probably make my way to Siskyou summit, or some other similar elevated position, and wait for winter. When the snow came in, the zombies would all freeze and I'd have the place to myself. Provided I had the right gear to survive the conditions...
Then, four words: heavily armored monster truck.
