Protesilaos Stavros has a lot of good content on Emacs and does nice deep dives on configuring both built-in and package-provided features. https://protesilaos

Protesilaos Stavros has a lot of good content on Emacs and does nice deep dives on configuring both built-in and package-provided features. https://protesilaos.com/ https://protesilaos.com/ Also available in video form on YouTube. I think he's a great resource for coming to modern emacs.