mythology nerds unite! I'm tying to learn more about Egyptian mythology and Japanese mythology too, but right now I know the most about Greek, Roman, and Norse mythologies
It's ok if you don't. And if you want to learn, I would say Rick Riordan's series don't really cover everything but they give you a basic idea plus they're great to read at any age.
You can learn pretty basic stuff with easy searches online too. I know teachers always say not to use Wikipedia, but I find that after cross-referencing info I find on there about mythologies it tends to be pretty correct.