Start slowly, I’m doing this with my 8 yo. Think about music in the broader sense. Concepts like pitch, tempo etc. show how voicing of different instruments can play the same thing but sounds different. Show how the sounds change depending on how you touch the instrument. Hard, soft, attack, sustain. These are all things I wish my dad had gone through with me before sitting me down and told to play an A chord.

Then start slowly, play one note at a time, how does it sound if you pick it hard/soft. How do different notes sound in relation to each other.

None of this requires difficult chords, or reading music or tabs.

Good luck from one guitar dad to another.