What can we do to have our best friend to perform our wedding ceremony?

Your best friend must be a judge or justice of the peace, the captain of a boat at sea, or a legally ordained minister of a religious organization in order to lawfully perform the marriage ceremony.

All this information is in the California Family Code Section 400. You can find this law online. I suggest you read it. First, you and your future spouse must both go in person to the County Clerk's office with a valid photo identification to buy a marriage license. The license is good for 90 days, during which you must get married or buy a new license to get married later. The persons allowed to marry you are a priest, minister, or rabbi from any denomination, or Judges of different kinds. A Native American shaman or medicine man may marry you. The duties of the marriage officiant are to know the California marriage law and to properly register the marriage with the California registrar. The officiant does not need to be registered with the state. It is up to the couple to decide whether the officiant is qualified or not. There are 2 ways to go about having your friend marry you. One easy way is for you to first be married by a County Clerk in his or her office. This is a simple ceremony that takes a few minutes and is inexpensive. Then you can later have your friend perform whatever ceremony you want at your wedding. This way, you know for a fact that the registration has been properly done. You will be having two ceremonies one perfunctory and one where your friend is blessing your marriage. This is the safest and surest way to have your friend marry you. A second way is to have your friend be a minister with some religion. Many people do this by buying a license online. Or your friend may already be some sort of minister. Your friend must then learn the California Family Code Section 400 and learn how to properly and promptly register the marriage. Then, your friend must register your marriage, with the proper witnesses and signatures. There is some risk that your friend will not do this properly, so you may be safer with the first method of having a state ceremony followed by your own personal ceremony.