Short answers, pulled from the story.
The New Testament contains 27 books written in Koine Greek. These include four gospels, the Acts of the Apostles, thirteen letters attributed to Paul, the Epistle to the Hebrews, seven Catholic epistles, and the Book of Revelation.
Athanasius, Bishop of Alexandria, listed all 27 books and used the word "canonized" to describe them in his Easter letter of 367 AD. The Synod of Hippo Regius in 393 AD may have been the first council to accept this canon, which was reaffirmed at the Council of Carthage in 397 and 419.
The New Testament was written in Koine Greek, the common dialect of the eastern Mediterranean world at the time. As Christianity spread, the texts were translated into Syriac, Latin, Coptic, Armenian, Georgian, Ethiopic, Gothic, and other languages.
1 Thessalonians is widely considered the earliest New Testament text, written around 52 AD. The earliest surviving manuscript fragments of New Testament books date from the late 2nd to early 3rd centuries AD, with the possible exception of Papyrus 52.
The New Testament has been preserved in more than 5,800 Greek manuscripts, 10,000 Latin manuscripts, and approximately 9,300 manuscripts in other ancient languages including Syriac, Slavic, Ethiopic, and Armenian. The text could also be reconstructed from quotations found in early church documents alone.
The word testament traces back through Latin testamentum to the Greek word diatheke, which the Jewish translators of the Septuagint chose to render the Hebrew brit (covenant) in the 3rd and 2nd centuries BC. In the Greek world diatheke referred almost exclusively to a will left after death, not an agreement between parties, which is what brit originally meant.