This is called a Petition for Custody and Support. How to fill out forms to start a custody and support case.Get the court address in the county where the child lives. Through the Petition for Custody and Support you are able to ask the judge to make orders regarding the issues of custody, visitation and child support only. If you do not want to file for divorce or legal separation, you may file a Petition for Custody and Support of Minor Children. This guide will take you through both of these processes, guiding you on which forms you need, how to fill them out, and how to start the filing process. Find and Download official court forms for California Child Custody and Visitation. Ready to take the next step? What forms do I need to file for child custody in California? GF-17. Petition for (Custody) (Visitation).