What major event at Pentecost begins the story of the church in Acts of the Apostles?

In the Acts of the Apostles, the major event at Pentecost that marks the beginning of the church is the outpouring of the Holy Spirit upon the apostles and other disciples.12

This event, described in Acts 2, is presented as the fulfillment of the prophecy of Joel regarding the pouring out of the Spirit in the new age. It serves as the transition from the earthly life of Jesus to the "new dispensation" of the church. The narrative notes that those present were empowered to speak in other tongues, an event often interpreted as a reversal of the Tower of Babel narrative, where languages were confused and people were scattered. This outpouring of the Spirit acts as the catalyst that leads the church from Jerusalem toward its eventual mission in Rome.31