Besides having an authorized person perform the ceremony, you need to have 2 witnesses at the ceremony. The witnesses need to sign your marriage certificate to prove they were there.
If your ceremony is being performed by a religious official, the ceremony must follow the traditions of your religion.
If the ceremony is being performed by a judge, court administrator, or other non-religious individual, you must declare that you take the other person as your husband, wife, or spouse at some point in the ceremony.