The best way to study the Bible at first hand is to use the King James Version (which is not without its flaws) in conjunction with Strong’s Concordance, which gives the Greek and Hebrew meanings relevant to the text.
(Note: I first linked by mistake to something called Strong’s Exhaustive Concordance, which at first glance, seems like a highly politicized version of the famous resource. It dispensed the familiar end-times narrative of political Zionism. Stick with the original Strong’s).
The Old Testament texts that Jesus read were in Greek (in the supranational Koine form), because the Greek version (Septuagint or LXX) was the most authoritative one at the time.
Here is an online version of the Septuagint with the Greek text next to the English.
It was called the Septuagint because, at least anecdotally, 70 (or 72) of the most important Hebrew scholars compiled it.
The Septuagint predates Jesus by a couple of centuries and was widely used in Alexandria in Egypt, where there was a very large Jewish diaspora.
This was the text used by the Church fathers when Christian doctrine was formulated in the first few centuries of the millenium.
The other authoritative Old Testament text, the Masora, was compiled over several centuries by Rabbinical scholars (Masoretes) between the 6th century and 10th century AD (that is, almost a 1000 years after the Septuagint).
It was a product of Rabbinical schools that were actively attacking and responding to Christianity and it should be understood in that light.
[Note: It isn’t necessary to ascribe a malicious motive to the Masoretes, although many Christian scholars do. From the Masoretes’ point of view, the Christians were simply reading things into the Hebrew text and they were taking a more neutral position. Both sides probably had some valid points.]
The Masoretic texts are the Old Testament texts used in the Talmud, which is the Rabbinical commentary on the Bible.
The Talmud, not the Torah, is the true core of modern Judaism.
Since the Talmud in both its Palestinian and its more famous Babylonian version were written down only in 200 AD (Mishnah) and 500 AD (Gemarah), the written records of modern Rabbinical (Talmudic) Judaism post-date those of Christianity.
Even the oral traditions of modern Judaism stem only from the Babylonian captivity, around the 6th century BC.
Consider that the earliest manuscript of the Talmud is the 1342 AD Munich Talmud.
By contrast, the first full manuscript of the New Testament, the Codex Sinaiticus, dates back to the middle of the 4th century AD or around 350 AD (a thousand years earlier).
In addition, there are fragments of the New Testament that go back much earlier, to the second half of the 1st century AD.
Altogether, there are over 25,000 early copies or fragments of the New Testament, not including quotations by the Church Father.
The New Testament is the most well preserved and well-documented piece of writing from antiquity.
Even so, understanding how the original Hebrew or Greek words have been translated into English is essential to understanding how meanings have been changed, either accidentally or intentionally.
In that respect, Strong’s Concordance is an invaluable resource.