Custody mediation and affidavits

Two questions…if a custody agreement made in mediation runs out does the parent that only got the children for visitation a few times a month now have as much right to the children as the other parent or does the agreement continue to stay in effect?
Also, if you’re advised to get teacher and doctor affidavits for court how are you supposed to do that…do you just ask or are there certain procedures that need to be followed?

If the agreement expires, and there is no court order to the contrary then both parents have equal access to the child.

An affidavit is the a sworn statement of an affiant, signed by the affiant, and witnessed by a notary.