A question about Jewish beliefs in relation to Christianity

I’m gonna preface this by saying that I myself am not Jewish, I’m agnostic/quasi-Buddhist, so my foundation of understanding for this religion isn’t super strong. Please take it easy if I get some things wrong, I’m not trying to be offensive or ignorant here. Also, when I wrote scripture, it kinda comes from the Christian version, because I couldn’t find any versions of the Torah that weren’t in Hebrew and I don’t know the language.

So, to my understanding, the Tanakh is basically the predecessor to what would later become Christianity’s Old Testament – mostly the same books, maybe in a different order, and with a much different view on the significance of it. But, as I recall, most of the stuff about what went on in Heaven largely tends to happen in Revelation in the New Testament – for example, stuff about Lucifer turning one-third of all the angels to his cause of becoming as powerful as God or Elohim or whatever name and eventually getting cast out of heaven, eventually leading full circle to Genesis where he’s most commonly perceived to be Satan crawling around as a serpent, seducing Eve to feed Adam the fruit from the Tree of Knowledge of Good and Evil.

So, what are the Hebrew beliefs about this? What went on in Heaven before the creation of Earth? Are there any details of this, or is it just kind of accepted to be beyond our limited mortal comprehension? Is it just that “the serpent” referred to in Genesis is just a snake?

That’s actually a major point that I’m curious about, is the serpent in the Garden of Eden. All the book actually says on its own (Genesis 3:1-5) is this:

Now the serpent was more crafty than any of the wild animals the Lord God had made. He said to the woman, “Did God really say, ‘You must not eat from any tree in the garden’?” 2 The woman said to the serpent, “We may eat fruit from the trees in the garden, 3 but God did say, ‘You must not eat fruit from the tree that is in the middle of the garden, and you must not touch it, or you will die.’” 4 “You will not certainly die,” the serpent said to the woman. 5 “For God knows that when you eat from it your eyes will be opened, and you will be like God, knowing good and evil.”

And then in 3:14-15, it says:

14 So the Lord God said to the serpent, “Because you have done this,

“Cursed are you above all livestock and all wild animals! You will crawl on your belly and you will eat dust all the days of your life. 15 And I will put enmity between you and the woman, and between your offspring and hers; he will crush your head, and you will strike his heel.

None of that makes any mention of the context of Revelation 12:7-9, which says:

7 Then war broke out in heaven. Michael and his angels fought against the dragon, and the dragon and his angels fought back. 8 But he was not strong enough, and they lost their place in heaven. 9 The great dragon was hurled down—that ancient serpent called the devil, or Satan, who leads the whole world astray. He was hurled to the earth, and his angels with him.

Without that to go on, it kinda just seems like the serpent in Genesis has nothing to do with Satan, the “ancient serpent who leads the whole world astray”.

This is, of course, all just one of many examples of things that cause significant changes in the importance and interpretation of the Tanakh or the Bible, a proof of concept. The overall question is what the Hebrew beliefs are about what went on in Heaven, but as I said, this piece of it is also one that I’m particularly curious about.