There’s a book called The Principles of Correct Practice for Guitar [0] that I found to be helpful. It’s not at all about playing specific songs or chords but entirely devoted to the mechanics of how to practice, how to hold the guitar, how to notice and relax tension, how to build speed, stuff like that. It’s a bit meta but I think it’d set you up with a good foundation.

[0] https://www.guitarprinciples.com/shop/the-principles-of-corr...