In the 25 odd years I developed software, I learnt all the rules the hard way.

Relax. You will make all the mistakes because the laws don't make sense until you trip over them :)

Comment your code? Yep. Helped me ten years later working on the same codebase.

You can't read a book about best practises and then apply them as if wisdom is something you can be told :)

It is like telling kids, "If you do this you will hurt yourself" YMMV but it won't :)