Reddit mentions of The Book of Legends/Sefer Ha-Aggadah: Legends from the Talmud and Midrash

A better sub for this would probably be /r/Judaism, since this one is mainly concerned specifically with critical examination of Biblical texts, rather than later rabbinical exegesis; at the very least, there are few people who could provide you with a good answer to this.

But before you get yourself into reading the Mishna, I think it's good to clear up some misconceptions that you have about the nature of the text. Firstly, the mishna is not a part of the Talmud; the Talmud was composed centuries later as a commentary on the mishna. Specifically, the mishna professes to be an oral supplement to the written law given by Moses at Sinai (and indeed, it was oral and practiced among the Pharisees for some time before being written down). As such, it's important to know that, contrary to what you wrote above, the mishna is concerned only with law. Additionally, before diving in, it's worth noting that the Mishna is divided into 63 tractates, and in sum totals hundreds of pages of technical material that is not even fully studied by most Jews; as such, I don't really suggest it as a primer to understanding "context on some parts of the Old Testament."

There are actually quite a few translations of the Mishna into English, and you can really just find them through Google. Artscroll, for example, is one of the more well-known brands (by clicking that link you'll get a pretty good impression of just how much Mishna there is). Since I don't suggest purchasing it, here is an online translation from Sefaria, which is an incredible resource of Jewish texts. That link will bring you to the first Mishna in the tractate of Berakhot; as you can see, a bit bland.

If you want old, more narrative-like interpretations of the OT, you should probably be looking at the books of Aggadah or Midrash. These tales tend to be scattered throughout the Talmud, but they're also collected in some works such as Midrash Rabbah and Yalkut Shimoni. Midrash Rabbah can also be found online here. Rashi, the most influential Jewish exegete, wrote a commentary on the Hebrew Bible that is the most studied commentary by Jews; in it, he quotes and explains these Midrashim. You can find his verse-by-verse commentary online also, here. Chaim Nachman Bialik, an eminent Hebrew poet from the modern era, also collected all of the Midrashim scattered across these works and composed a single volume called The Book of Legends; the legends about the Biblical books can be found in chapters 1-9.

To be honest, it's not so easy to just pick up a Talmud and read it and get what's going on. It's primarily a legal text and the parts you'd find interesting are the occasional tangents it goes on, but even those are there to make a point about the law and are presented in the same argumentative style.

So you'd probably be more interested in an anthology of "Aggadot" ("tales"), such as this one (I have no idea whether that particular one is good or not, I just found it through a Google search, though the Amazon reviews are good).

I love the English translation of Bialik and Ravnitzky's Sefer ha-Aggadah --- your local library might have it.

At that age, I was going to my shul's youth minyan. It ended early, and the Rabbi who led it read this book to us, and gave us prizes for remembering the stories. It was awesome.