It would be wise to establish paternity prior to paying support and paternity would need to be established prior to an order for support being entered by a court (assuming the mother and alleged father are NOT married.)
A father is free to provide support to anyone he wants without a court order. In order to be court ordered to pay child support, the court must be involved, which usually means establishing paternity, voluntarily or involuntarily. A local attorney can assist you with further questions.
I agree with Attorney Korr. I would also add that if you have questions regarding support, you should contact a family law attorney in your area. If you have court orders, you need to follow the order. If you have a summons and complaint, you need to make sure you pay very close attention to the dates. Best of luck.