Hi, I'm an old man speaking only poor school english.
I wrote a german articles series named "Installation Guide for Paranoid Dummies" as posts in our Gentoo Forums. It is focused on security and uses only OpenRC. In my starting post you will find links to more articles explaining FireWall, SecureBoot, encryption, AppArmor and some more. If you speak german you might be interested in it: 
- Dirty Pipe: https://dirtypipe.cm4all.com/