The Ancestors of Jesus
Luke 3:23 (CEV)  When Jesus began to preach, he was about thirty years old. Everyone thought he was the son of Joseph. But his family went back through Heli,...

 He never had a 'ministry' in the sense that we know today. In the eyes of his Jewish contemporaries he was a 'wandering rabbi' - a Jewish tradition that remained very common all over middle and eastern Europe until WW 1, including the disciples and the miracle stories attributed to them. Since he died in his early thirties, it is probable that he had been 'active' so to speak for the last 5 (probably) to 10 years before that. That would have made him some 25 years old when he started preaching.