OP, I think there's an option missing from the list, a good old book, you know those things made of paper with printing on them.
In 1962 or thereabouts, when I started, there were no tutors, teachers, internet, tab, songbooks, etc. The only way to learn how to tune the bass, basic scales and chords was the book written by Chas McDevitt and Shirley Douglass, the name of which escapes me for the moment however I'm rather envious of the fact that Happy Jack actually still has a copy of it.
After that it was by ear, transcribing everything by hand.