Can I get some legal advise on steps to child custody and divorce>

You can either file for dissolution or you can wait for him to file the papers. Once the dissolution papers are filed, you will want to file an Order to Show Cause to seek temporary orders to establish child custody/visitation and obtain orders for Child Support and Spousal Support pending trial. Also note that there is a 6 month waiting period from the time of filing until you can obtain a divorce status. CA is a community property state. Generally speaking the assets and debts aquired during the marriage are community property and the respective spouses will be entitled to half of the the value of the assets and will be responsible for half of the debts. The parties can however negotiate regarding this. For ex. one spouse keeps the community residence and takes over the mortgage and pays the other an equalization payment for their respective half of the equity. Also note that California is a no-fault state. The court's will not penalize infidelity and generally speaking will not take it into account.