You must apply for a marriage license in the county where you intend to get married prior to the wedding. Once you have your marriage license, you can have your wedding ceremony within that county after the required waiting period has been met and as long as the marriage license is still valid. After your wedding ceremony, the marriage certificate must be signed to validate your marriage. Making a mistake in this process could nullify your marriage.
Meet with your officiant and at least two witnesses -- typically the maid of honor and best man -- directly after the ceremony to sign the marriage certificate. Arrange this in advance so all parties are present.
Sign the marriage certificate using the name that appears on the marriage license, not your new married name. The bride and groom both have to sign the document.
Have the officiant and your witnesses sign the certificate. Once all signatures are in place and the signed certificate is filed with the county clerk's office, your marriage is legal and valid.