What comes first?
You have to get a marriage license before you can get a marriage certificate. The license is a document that gives you authorization to marry. State laws vary in terms of expiration date, waiting periods, and fees. Most require applicants to show up in person at the local clerk's office and have a valid photo I.D. Research the rules pertaining to the state where you're marrying. In New Mexico, for example, an engaged couple is issued a license immediately at the county clerk's office (if they pass certain requirements); there's no waiting period, and the fee is $25. In Alaska, the waiting period is three days from the time the license is issued; the license is valid for three months and costs $60.
What are the requirements?
To get a marriage license in most states, the couple must be at least 18 years old or, if younger, have consent from a parent or judge. If either of you were married before, you'll need to show proof of your divorce or annulment. Both parties must be mentally capable to understand what getting married means, and they can't be closer than third cousins. Blood tests aren't required in any state.
Where do you get a marriage certificate?
You don't—that's the job of the officiant (clergy member, judge, mayor). It's a document that you, the groom, officiant, and witness sign right after the wedding to prove you got married. He or she is expected to file your marriage certificate with the county clerk, registrar, or other recording agency where the wedding took place within a few days. Once the certificate is processed, you'll be sent a certified copy.