Jesus is invited to a wedding in Cana, with His disciples. He is already respected as a teacher in His own right. The 6 stone jars are used for OT ritual cleanliness. Jesus uses them to bring wine to Israel, when they only had water - or even not-as-good wine - before. Jesus provides joy and gladness at His coming. Do you expect joy from His salvation?
Jesus' authority is questioned when He drives the sellers and changers out of the temple. Again, He points not to the temple (or jars) of stone, but to Himself. He prophesies His body will rise 3 days after it is destroyed. Do you trust in buildings of stone or in the sacrificed body of Jesus?
Apparently Jesus did other signs in Jerusalem, so that many believed. But He didn't let them sway His mission.
Jesus teaches the teacher, but at night. After that temple incident, the establishment is against Jesus. Jesus establishes the tension early on between His signs confirming Him as from God, and His other actions setting Him against the wicked shepherds of Israel. One must be born again by water and Spirit to enter the Kingdom. Jesus must be lifted up to accomplish this eternal life. God sent Him so that whoever believes in Him will live forever. Believing in Him means coming into His light, and forsaking deeds of darkness.
Disciples notice the competition between Jesus and John, and John says Jesus is supposed to increase. "I'm just the messenger; He's the real Groom, come for His bride." The message strengthens from "Jesus has life" to "without Him you are still under God's wrath."
Again, Jesus is greater. This time, greater than Jacob, who dug the well. Jesus speaks with an immoral, Samaritan woman - something that just wasn't done. But Christ's mission transcends social convention and Jewish provincialism. She evades His convicting words with a theological discussion about worship. The reason for His speaking to her comes clear: she can worship Him without going to Jerusalem or Gerizim, in the Spirit. He is the Messiah she is waiting for. She leaves her water, having living water to give to others inside now. The disciples are eager to eat lunch, but also ready to spurn the society of the Samaritans they got it from. The woman reaps a harvest of Samaritans, bringing them to Jesus, and more laborers are needed as they all believe. Who in your life may be ripe for the harvest, that you can bring to Jesus?
Finally, Jesus heals an official's son, which by John's count is the second sign, though Jesus did many signs in Jerusalem after the wine at Cana. Hm. The man believes on Jesus' word, instead of on His miraculous deeds, which Jesus points out is better.