How to fill out forms to start a custody and support case. Get the court address in the county where the child lives.You can file a Request for Order (form FL-300) to ask the judge to make or change an order in that case about child custody and visitation (parenting time). The mission of the Santa Clara County Department of Child Support Services is to promote the well-being of children and the self-sufficiency of families. Form Packets – Child Custody and Support. The Family Law Facilitator's Office offers assistance with the completion of legal forms and provides procedural guidance in most areas of Family Law. If there are children involved, child custody and support will also be considerations. Once you've filed, you will be given a file number and your petition will be stamped as received. To start, you will need to fill out the application packet(s). Meet Residency Requirements: At least one spouse must have lived in California for at least six months before filing for divorce in the state.