California desert camping
All supplies should be brought in if not for the mere fact that obtaining supplies in the region can often be pricey. Remember though, the desert can be a desolate and unforgiving land, always bring more than you think you will need. Campfire BBQ's and fresh fruit are certainly treats for which you will develop a new found appreciation for. And typically, as Car Camping is the desired approach, you can feel free to bring in almost all that you need.
A couple of suggestions for meals:
Beef jerky and the road also go well together as long hours on the journey need a bit of flavor. Notable is a small shack on Interstate 395 simply named 'Fresh Beef Jerky' in Olancha. Its $20 for 3 packs, but its fresh made and quite frankly the best jerky around. There's plenty of pickled vegetables and free samples also.
Bring plenty of water. A standard rule of thumb is 2 gallons per person per day. Of course this can be partially substituted with fruit juices or sodas, but make sure that you have more than you think you'll need, particularly if its your first time venturing in.