We have no idea which miracle the historical Jesus first worked. Our four Gospels aren’t much help in determining the event. Each evangelist carefully chooses Jesus’ first miracle. It sets the theme for the rest of his Gospel.
Only in John’s Gospel do we find the changing of water into wine at Cana as the first miracle Jesus performs. There are two keys to understanding its meaning and the theme John is creating. First, throughout his Gospel, John never refers to miracles as miracles. He always calls them “signs.”