Is an inheritance from an individual's family member, such as a grandparent, community property, or does it belong exclusively to the person it is willed to, in the state of California?

Would money inherited before marriage become community property upon marriage, in the state of California? Should such funds be protected and how would an individual do that?

It is not community property. To protect the asset you can just hold it separate from the community assets and try not to comingle anything.