Earlier quoted context omitted.
What W3C resources have you been using?
We've been using this one: https://www.w3schools.com/html/ He's had no trouble at all following along and using their tooling. I've been mostly hands-off. I'm about to graduate him from "do it in just the browser" to using GitHub pages. That way he can have an HTML site that's "his" and start putting the pieces together.
That way, when ever he is filled with self-doubt and needs reaffirmation, he would be able to put things together from the ground up and regain confidence.