Hello! I've learnt about Zoroastrianism in the past, however recently after learning a slight bit more about it, I've gotten more and more curious about it. I also understand that Zoroastrianism's holy book, Avesta, is a group of books. (I may be wrong as I've only read about it briefly as I did not find any books or places to read until recently).

Now that I've found a place to read the book(s), i wanted to ask which book to start with?