You don't need to know the history of Natasha Romanov (AKA Black Widow) to read this book. If you've never picked up a comic in your life, ever had any interest in superheroes don't let that stop you from having any interests at all. You don't need to know the whole history, know the artists, writes, issue numbers, or volume collections. Even the differences between the movies and the comics and pick them apart. What's important is you have an interest in something; I think it's wonderful and you should grow that interest. If you're interested in getting into it, this book is a perfect start.
I got Forever Red book during BEA/BookCon, and it's been sitting on my shelf for months. At first, the title sounded like a Taylor Swift song to me (later on I found out it's actually a perfume from her, ha) but I finally got around to reading it and I finished it in 3 days. It was so good. It's a YA book from a YA writer, Margaret Stohl, from famed Beautiful Creatures series. She's an unexpected author for Natasha but captures her so well in her writing, it gave me a better glimpse of her character beyond the comics. Natasha is fighting off her emotions but even after years of suppressing what happened to her in the Red Room (a Russian operation to train young orphan girls to become assassins and spies) she deals with her deadly father figure. There's a new character, Ava Orlova, and without giving much away, and they help each other throughout the book in unexpected plots with an adventurous twist.
Marvel doesn't have much marketing on Black Widow so I was surprised this book was published. At this point, as a Black Widow fan, I will take anything I can get, and this is a book I will happily support. If Marvel notices a jump in book sales, maybe they'll finally bite for a movie. Preorder the book here.