I have been raising Gambel's which are closely related to the Californias. This is my first time raising them but maybe I can help a bit, since I'm assuming they've hatched or are close to hatching now.
I have a group of 9 quail that are over-wintering together. They are all about 4-5 months old right and I've seen the beginnings of what looks like pairing behavior. It is a bit early but I think the funky weather is throwing them off. Or they might just be practicing, since they're still quite young. For CAs you do want pairs (they are monogamous) and pairs that are house separately because they do get very aggressive during breeding season. Unless, as is already said, you have a huge outdoor space where they can get away from each other. As I understand it, the female chooses the male, who tries to woo her, so you'll want to keep your babies together in a group during winter and let them choose their mates.
As for food, I kept mine on Gamebird Starter while they were chicks and through them getting their adult feathers. Now that they are mature, I have switched them over to 24% chick(en) starter. They also get a bit of seed mix and greens from the yard (grass, chard, dandelion, clover, etc) plus whatever bugs they munch in their aviary. Baby Gambels/CA quail eat a lot of insects in the wild, hence why they need a lot of protein as chicks, but adult quail have a very different diet and the protein level should be lowered or you will have health problems.
