Where do I sit the groom's parents? I need to give you some information first. His mother has remarried, so the groom has a step-father. He calls his mother's ex-husband his daddy since this man adopted him when he married his mother but his biological father will also be at the wedding. I have not met his biological father. He wants to escort his mother in and the man he calls daddy. A friend of his is going to be his best man and I don't know how to seat these 3 people. Please help me with this.

His mother and step-father would be seated in the first row of people on the groom's side - current husband would sit with his wife (in non-Jewish ceremonies this is on the right as you face the front). His biological father could be seated in the third row - right side. Second row could be siblings or grandparents.

I'm not clear if there are two step-fathers here (you say "daddy" is his mother's ex-husband?). If so, you could space them with a row in between each - unless they get along with each other, in which case they can be seated together if you and they like.

Many times the very first row is left empty in case someone from the wedding party needs to sit down quickly, so all guests are seated beginning in the second row. This practice may vary by location and officiant.