I did a quick little article on creating your own lore for players to read in your own game.
You can read here:
https://www.secretsofblackmoor.com/blog/making-lore-for-your-campaign
I like it. Similar to what I've been writing (in idea but not content). I wrote short paragraph stories the story usually goes into detail here) written as rumors or tales overheard again and again. I did this for most of the religions. Not details of mythology but how the cults act.
For example I have the god of war and combat the Templars are basically drunken frat boys and every story ends with bloodshed. Nobody can prove they were involved in the killings, but players will quickly pick up on how dangerous these guys can be. If they don't pick up on that, well it may be painful when they learn.
Another cult, of health and love has bath houses that are basically whore houses that pay for hospitals that take care of pregnancy issues. Screw with the priestesses and they may shut the baths. If the shut the baths the drunken frat boy Templars mentioned above may take a dislike to you. So be careful when dealing with them as well.
I haven't dealt with ancient history stuff yet but it will probably be similar. I expect to provide handouts do they can read it all and refer as necessary.