When you attend the pre-visit the centre will allow you to see the building and will hopefully be able to identify the room that your child will be spending time within. Ordinarily, parents would not be in the contact room whilst contact is taking place. This would require both parents being together at the same time and in most cases if this were possible you probably wouldn’t need the services of a contact centre.
If your child is particularly unsettled centres will have ways of managing this. One of these might be that you join your child in the contact room (maybe with or without the presence of the other parent), you would then spend time calming your child, progressing to playing with them. Then when appropriate you would be expected to become less a part of the play, and moving towards gradually leaving the room and being replaced by the other parent for the remainder of the session. It is anticipated that once the child forms positive associations with the centre and the person they are having contact with this could become less needed and cease.