Best case scenario is that the company you are going to work for has a benefits package that includes health care. If so it should also cover your family as well. You will probably pay a small amount each month out of your pay to subsidize the cost of the policy.

If the company does not offer health insurance you have a couple options. You can signup through a state exchange (cheaper, subsidized by the government with fewer choices for coverage) or directly with the insurance company (more expensive more choices for coverage).

That is it simply put. I don't know how this affects you if you are not a citizen of the US and there may be other options in California specifically. I would check with the company and if they have an HR person them specifically. They should be able to guide you more specifically.