deFENDER

Hi, I have been playing guitar on and off for about 35 years and perhaps the on and of bit is part of the problem. Most of my learning is self taught by leaning the how to play various tunes using YouTube videos tutorials. Whilst this is fun and I have learned quite a bit from learning to play my favourite Hendrix tracks for example, most of the time I am playing notes and chords and couldn't even begin to tell you what they are. Perhaps what is needed Is a step by step guide on the fretboard, scales and music theory that is online something perhaps like youcian or Fender play? Any advise please.