I often find Agatha herself frustrating but the books are an easy read; she's often described as an unlikeable heroine though, so it's intentional.

I would rec this one if you can borrow it from the library! I did remember certain myths as I read but some parts I'd never heard of. Greek myths were also the ones I read most when younger. The Egyptian and Celtic ones came much later.
There was a great Young Adult series I read when my younger sister had them from the library with a lot of Norse elements The Forbidden Game by L J Smith creator of the Vampire Diaries books.
Also the New Zealand show "The Almighty Johnsons" had the characters as reincarnations of Norse Gods, waiting for the reincarnation of Odin so they could return to Valhalla. Again, some characters I was familiar with, others less so!