They have no wine.

John 2:11 This beginning of miracles did Jesus in Cana of Galilee, and manifested forth his glory; and his disciples believed on him.

They have no wine.
1. Perhaps as a consequence of poor planning. "Shortage of provision when guests are invited is considered a sore humiliation the world over" (The Fourfold Gospel by J. W. McGarvey and Philip Y. Pendleton)
2. Perhaps as a consequence of poverty.
3. Perhaps as a consequence of intemperate guests (or a larger number of guests than were expected, see 1).

Not one concern of ours is small
If we belong to Him;
To teach us this, the Lord of all
Once made the iron swim. (John Newton)

[Or in this case we could change it to "Once made the water wine."] Whatever might be said about this miracle, there seems to be at some intersection in its meaning and the idea that all the hairs of our head are numbered, and that not one sparrow can fall without God's involvement. God is involved in all the details of our lives, even the "minor" ones like refreshments at a wedding.

"It is part of Christ's system to reserve the best until the last. Sin's first cup is always the sweetest, but with God that which follows is ever superior to that which has preceded it.

"The value of the miracle was in what it signified, not in what it wrought. It manifested the glory of Christ, part of which glory is his power to change the worse into the better..." (The Fourfold Gospel by J. W. McGarvey and Philip Y. Pendleton)

"...the glory of his deity and divine sonship, which was hid by his assumption of human nature, but broke forth and showed itself in his miraculous operations..." (John Gill)