You can also check out WoWpedia and read up on specific characters or areas you're not familiar with.
You can also check out our lore primer, which condenses everything up to the Battle for Azeroth expansion into an even-easier-to-digest read with helpful TL;DR sections that really give you a quick overview of what's happening and why.  You can also check out WoWpedia and read up on specific characters or areas you're not familiar with. Over time, all that knowledge will start to form a comprehensive understanding of Azeroth and its history.