I’m going through a course on the history of the Catholic Church, and here’s something I didn’t know before:
There’s a document called the Muratorian Fragment, which is the oldest list of canonical books known. The document itself is from the 8th century, but is a Latin translation of a Greek text (that we don’t have) from somewhere around 180 AD.
Some of it is missing (thus the name “fragment”), but here is a translation of the beginning of it:
. . . at which nevertheless he was present, and so he placed [them in his narrative].  (2) The third book of the Gospel is that according to Luke. (3) Luke, the well-known physician, after the ascension of Christ, (4-5) when Paul had taken with him as one zealous for the law,  (6) composed it in his own name, according to [the general] belief.  Yet he himself had not (7) seen the Lord in the flesh; and therefore, as he was able to ascertain events, (8) so indeed he begins to tell the story from the birth of John. (9) The fourth of the Gospels is that of John, [one] of the disciples. (10) To his fellow disciples and bishops, who had been urging him [to write], (11) he said, ‘Fast with me from today to three days, and what (12) will be revealed to each one (13) let us tell it to one another.’ In the same night it was revealed (14) to Andrew, [one] of the apostles, (15-16) that John should write down all things in his own name while all of them should review it.
The rest of it can be found |HERE|. The document does not contain a complete list of New Testament books as we know them today. The earliest list of all 27 books of the New Testament (and only those 27) doesn’t appear until something around 360AD.