Hi, I’m a California lawyer. I’m not your lawyer and this is not legal advice.
Other comments on here are close but not quite right. Without a will, your husband’s possessions pass to surviving relatives by way of what’s called Intestate Succession.
In California, that system allows for some things to pass to the spouse, some to pass to children, and, if no children or spouse, things pass to various others.
Here, if you are his common law spouse (which has strict requirements), you will receive portions of his personal and real property. His children will also receive portions. There’s also something called a homestead exemption that would prevent his kids from taking or doing anything to your home. All of this is very basic and general information, and an attorney will be able to help you.
Long story short, Google “California common law marriage” and see if you qualify. Whether you think you do or not, get a Wills and Estates lawyer. Like, yesterday. The lawyer will help you with next steps.
Very sorry for your loss. This gets much much less confusing after you have a lawyer on your side. Best of luck.