I’ve actually played for some time. I started when I was 18, and now I’m 52. 
But I’ve never learned it all from start, and I think I’ve missed important stuff like music theory and common practice. For instance I’d never heard about muting the E string, even if I do play alternating G as base in the C chord. I will learn it all now!
Justin is great, your answers to my question are also top notch. Thanks!