All the apostles preached and baptize in the name of the Trinity.  The first community becomes and action group. The new community grows by the grace and gifts of the Holy Spirit.  We see in this scene Peter Baptizing an adult and Paul preaching the Word of God.

Council of Jerusalem.

Some who had come down from Judea were instructing the brothers, “Unless you are circumcised according to the Mosaic practice, you cannot be saved.” Because there arose no little dissension and debate by Paul and Barnabas with them, it was decided that Paul, Barnabas, and some of the others should go up to Jerusalem to the apostles and presbyters about this question. They were sent on their journey by the church, and passed through Phoenicia and Samaria telling of the conversion of the Gentiles, and brought great joy to all the brothers. When they arrived in Jerusalem, they were welcomed by the church, as well as by the apostles and the presbyters, and they reported what God had done with them. But some from the party of the Pharisees who had become believers stood up and said, “It is necessary to circumcise them and direct them to observe the Mosaic law.”
The apostles and the presbyters met together to see about this matter. After much debate had taken place, Peter got up and said to them, “My brothers, you are well aware that from early days God made his choice among you that through my mouth the Gentiles would hear the word of the gospel and believe. And God, who knows the heart, bore witness by granting them the holy Spirit just as he did us. He made no distinction between us and them, for by faith he purified their hearts. Why, then, are you now putting God to the test by placing on the shoulders of the disciples a yoke that neither our ancestors nor we have been able to bear? On the contrary, we believe that we are saved through the grace of the Lord Jesus,g in the same way as they.” The whole assembly fell silent, and they listened while Paul and Barnabas described the signs and wonders God had worked among the Gentiles through them.