First, apply for a marriage certificate online, and the go to the Registry office on an appointed date and time. Once you have collected the certificate, the signing can be done during your wedding solemnization. You will have to get a solemnizer to officiate the marriage and signing. Usually you might have to write your name followed with a signature of your own. Make sure to use a good pen for this occasion!
I'll be funny and say, use a good pen to sign on your marriage certificate. But I digress. If you mean that you would like to get a marriage certificate, then you should find a partner who would like to marry you, and apply for a marriage certificate in your area's marriage registry. You will have to go through a series of processes depending on your government, and will only get to sign it on the day of your legal wedding solemnization.
Each state has its own laws that govern who must sign a marriage license, but the certificate will be a government-issued, usually embossed, official document that says you are now married. You don’t sign that document or you’d be defacing it. The license the document issued by the state before your wedding. It’s the license that must be signed, usually by the officiate and two witnesses, and sometimes by the bride and groom. The rules vary by state, but they are usually posted on the state’s official website and you can often use the same website to submit an application for a marriage license as well.
Couples obtain a marriage license from the relevant authorities, hold the wedding ceremony. Both spouses, along with the person who officiated over the marriage, along with one or two witnesses, sign the marriage certificate. This is usually done just after the ceremony. The person who performed the ceremony will file a marriage certificate in the appropriate office within a few days. The married couple will receive a certified copy of the marriage certificate.