There are a number of occasions where we are told that the early Christians got together, for various reasons. I'm not sure that I have found them all, and I may have misinterpreted some, but here are brief descriptions of several times when the Christians joined together, or when people who were about to become Christians joined together, as found in Acts, and copied from the World English Bible, which is public domain:
2:1 Now when the day of Pentecost had come, they were all with one accord in one place.
2:46 Day by day, continuing steadfastly with one accord in the temple, and breaking bread at home, they took their food with gladness and singleness of heart, 47 praising God, and having favor with all the people. The Lord added to the assembly day by day those who were being saved.
4:23 Being let go, [from being arrested, Peter and John] . . . came to their own company, and reported all that the chief priests and the elders had said to them. 24a When they heard it, they lifted up their voice to God with one accord,
16a As we were going to prayer,
11 Now these were more noble than those in Thessalonica, in that they received the word with all readiness of the mind, examining the Scriptures daily to see whether these things were so. 12 Many of them therefore believed; also of the prominent Greek women, and not a few men.
They said to him, “No, we haven’t even heard that there is a Holy Spirit.”
3 He said, “Into what then were you baptized?”
They said, “Into John’s baptism.”
4 Paul said, “John indeed baptized with the baptism of repentance, saying to the people that they should believe in the one who would come after him, that is, in Jesus.”
5 When they heard this, they were baptized in the name of the Lord Jesus. 6 When Paul had laid his hands on them, the Holy Spirit came on them, and they spoke with other languages and prophesied. 7 They were about twelve men in all. 8 He entered into the synagogue, and spoke boldly for a period of three months, reasoning and persuading about the things concerning God’s Kingdom.
*A text note indicates that the word translated as "brothers," could have been translated as "brothers and sisters," or "men and women."
Thanks for reading. Read Acts.