They are right.
Doesn’t matter if you have Mac, PC, Linux, or a Chromebook. Start with a simple text editor, and barebones HTML.
More than once, I’ve been able to fix something with someone else’s computer, out in the field with just those tools.
And more than once, those fancy CODE editors, screwed up my design, and I had to go old school.
Learn old school with old school tools.
I’ll make some other suggestions along the way.