If the father has filed for custody and has physical custody and the mother is trying to take the child when she has nothing for him no car no house and no baby things what can he do?

How is she trying to take the child? Grab the child and run? Take the father to Court?

The father (who has apparently filed) goes to Court and proves the mother is unfit. PROOF is necessary.

They need to get it settled in court, unless the mom is proven a danger to the children, most likely she will get visits