For me the key phrase here is this was the first of Jesus’ signs: it was at Cana in Galilee. John is telling us how to read this story.
We sometimes get into tussles about historicity. The Jesus Seminar folks tell us this story never happened because we have not supporting documentation. The biblical inerrantists tell us every word of scripture is an historically accurate picture of actual events. But John says this: read this story as a sign. Signs point away from themselves to other things.
I’m reminded of a zen proverb. When the finger points to the moon, only dogs look at the finger.
So what does this pointing-finger story point to?
Three days later. It points to the resurrection. Transformation. A new creation.
Water into Wine. This is water meant for ablutions. Ritual washing of the outside. But this is good wine. Wine that changes us from the inside. Transformation and new creation yet again.
So what do we do with it?