Read about what they did beginning with Acts. The Catholic Church is the outgrowth of ALL they did. Remember, they did this for the first 70 years with nothing written. It is also useful to get some other perspectives from the fathers, the Didache and other relevant sources, especially when so much happened in the growth of the Church before the Canon was assmbled.
As to the Bible, grouse all you want, but the Catholic Church is the organization that assembled the Canon and continues to infallibly interpret it down to this day, and yes, before you go there Sacred Tradition also transforms us as Catholics.
Sounds prideful to me.
“but the Catholic Church is the organization that assembled the Canon and continues to infallibly interpret it down to this day,”
God Word is sufficient.
The Catholic church is not infallible. If you believe that, I've got an indulgence to sell you. Historical instances of abject corruption in the Vatican refute any such claim. No creation of man is infallible, not Catholic, not Protestant, none of them. We're all fallen and find salvation only through the grace of God, and those who repent and accept that salvation consitute the Church. This even applies to the Pope.