One note: the church is setting up a heirarchy. Peter and a group of unnamed elders were at the very top, underneath them were The Twelve, underneath them were the leaders of the various city churches. The Catholic church has codified this heirarchy, proclaiming Peter to be the first Pope. I don’t buy it, but I can see an internal logic to the Catholic’s argument.
There’s also a bit of a split in the church already. Well, specifically within The Twelve. Barnabas and Paul were going to go out on another evangelical mission. Barnabas wanted to take John with them, but Paul refused, saying that Mark had not done as much work as the others, and wasn’t worthy. After a lot of fighting, they ended up splitting up, with Paul going alone to Silas while Barnabas and Mark headed off to Cyprus.