guides to know all about self host? (for beginners )

I want to self host some services for me and my first questions is: Any guide or book, or wtv, you recommend to understand self host world? I want to understand all things about it, but dont know where to start. And the guides for beginners i found on internet are very basic, just seems things like "do that, do this, and go" . I want to fully understand the world of self host. I want to understand firewalls, DyanmicDNS, MeshVPN; How to do self host; what not to do, what precautions, etc, etc. thx