What more do I need to marry people?

As a lark a few years ago I got an online ordination by the Universal Life Church (http://www.ulc.net/). Someone at work mentioned planning an outdoor wedding next spring. We started talking and it came up that I was ordained. She was open to the idea of me marrying her to her fiancé. But I don’t know what more I need to do. When my nephew was married, it was done by someone ordained by the ULC as well. If I had known at the time I would have talked to the “minister” about it. That was in the state of Washington. I am in California. Does anybody know if there is something else needed (other than the marriage license of the couple) from the state in order to perform marriages?