Hey pal, do follow the tutorial. Music keys, scales, chords + progressions, baselines, melodies, etc are all covered with examples and/or exercises. It's not as deep as a full music theory course but I don't think anyone is claiming this will get you a music major ¯\_(ツ)_/¯.

It even has an advanced topics section with an intro to pentatonic and octatonic scales, triads and inversions; check it out in the menu.