So I'm going to talk about why there are no Hebrew bibles from this time. Since Jesus died in the 30s, for most of that period there couldn't've been an intact New Testament.

We do have biblical texts from this era. The Dead Sea Scrolls span a few centuries, including the 1st century and before. Here's a thread about it. But they don't do a ton to "give a more authentic look at the bible's original message". They illuminate what the words originally were, and helps to figure out what's a scribal error. And they do show some things that may've been altered, such as Deuteronomy 32 discussed in the other thread.

But the real challenge in figuring out what the bible's original message is isn't figuring out what the text actually reads. It's figuring out what the text meant. We do have some theology from the community that wrote the scrolls, and from other sources during the period. But they're writing theology of different sects centuries after the biblical texts were originally written (depending on which books and your preferred biblical dating scheme).

As for why they're not intact, most writing material doesn't survive 2000 years terribly well. There were several wars in the area at the time, which would've destroyed a great deal of written material. Also, written material was written on scrolls. Because you have to...scroll through to get to anything, it's not practical to have a big honking scroll of the whole bible. The biggest thing written in a scroll in Jewish tradition is the Torah. Other scroll-texts are shorter.

As has been noted by other, there was no Canonical Bible as we know it until about the 4th Century. There were disparate works, some of which became cannon, many others became what are known as The Apocrypha. Either they were not considered "Divinely Inspired", were contradictory, or were outright "heretical" or "blasphemous", and were not included in the official Western Cannon.

In fact, in this day and age, the Catholic Bible has a few more books than most Protestant bibles! This is just for the classic Catholic/Protestant split that occurred with Martin Luther and the Reformation. There are actually multiple different "Bibles" floating around..

Between the death of Jesus and the final stages of codification, there were multiple different sects of Christianity, some of which are considered heretical today. Marcionism, Montanism, Arianism, as well as Nestorianism.

Thoughout most of the 1st Century, there really wasn't a need to write down much of what would later become the Gospels, as the direct follows of Christ were still alive and speaking. It was only later in the late 1st and early 2nd Century would there have been a pressing need to record the actual Gospels, or Logia, that Christ himself stated. In fact, the oldest known book of the Bible is from ~50 A.D. and is First Thessalonians, one of the Letters of Paul.

By around 140 A.D., with growing disparities between the various Bishoprics (Alexandria, Jerusalem, Antioch, etc.) and their teachings and values, it was beginning to become clear that some sort of consensus of "okay, what is it we believe, exactly?" needed to take place. In fact Marcion, of Marcionism, a heritical belief, stated that there needed to be an official cannon and compiled his own. Though later considered to be Heritical and Gnostic (he taught about the Demiurge), it was the first attempt to decide which scriptures were the formalized writings of his belief structure.