I think you might be jumping the gun a little. The first lesson would probably be the basics such as finger nail care, holding the guitar, tuning etc and ending with an assignment for learning to play and change from 2 or 3 chords smoothly. Show them the chords and simple strumming and give them chord diagrams for practicing at home.
Unless there are simple cowboy chords (probably not) I'm not aware of for AHWNO, it would be pretty advanced for a beginner both in the chords and the strumming.
A very old song (1967) that only has 3 easy chords in the verse, Em-A-Em-C is very easy in chording and strumming.
https://www.youtube.com/watch?v=qhYLz63csS0
https://www.e-chords.com/chords/stra...nd-peppermints