How to perform court marriage?

I want to do a court marriage, but the problem is that my mother knows everything and wants some assurance or security. However, no one from the boy's family knows about our relationship or the marriage plans. Due to time constraints, he doesn’t want his family to find out about the court marriage right now. We do not have the original documents, but we can provide photocopies. Our main concern is: if we proceed with the court marriage, will any notice be sent to the boy’s home? We do not want his family to find out at this stage. Please guide us through the process and also let us know the approximate expenses involved.