So what are you up to?
Are you writing new music?
Are you learning for your enjoyment?
Are you just trying to archive something you feel you never completed in your youth and learning the theory will fix some hole?
Sounds like you’re using your lack of theory as an excuse not to free wheel it. What skill level do you need to archive before “You” will feel “You” are ready to free wheel it.
Some things in life do not need best laded plans or pre-thought put into them. Some things just need to be released as they move through you.
Let go of control, pick up your guitar, close your eyes and start to play, see what comes out. If you find yourself playing someone else's music, you still need to let go of control. Let what is in you come out.