I am not a musician (beyond basic open and barre chords), so I would appreciate advice. My teenage son has been learning guitar for about a year from YouTube and is at the point where he can print song lyrics and write the key and the chords in Nashville numbering and strum along to the records. For example, Blues Traveler Run Around, Key of C, I-IV-vi-V.

He has no experience in lead guitar or coffee shop type playing where you mix lead and chords.

I am wondering what to do next to help him develop. Lessons with a teacher are not possible due to cost, but I can pay reasonable website subscriptions.

I heard Jens Larsen Jazz Roadmap can take people with little experience and teach them how to substitute chords and play leads.

If Jens's course is not an appropriate next step, what would you recommend?

Should I have him learn CAGED before starting the Jens course? I do not know CAGED, but there are free tutorials on YouTube.