What are good resources for reading up on ‘classic’ lore for big name entities in 5e like the demon/devil lords and some of the long-standing entities?

I'm sure things have changed a fair bit edition to edition, and I'm aware that different 5e settings have their own version of big names, but are there any places to get a quick rundown for them?

Idk shit about Corellon, but he seems cool. I wanna learn the basics. Same with Asmodeus, Lolth, Corellon. Idk what the established lore is. I understand the very basics bc of the 5e books that mention them, but l'd love to know more.