[tex4ht] Advice on where to start?

[Karl Berry]

    Sorry to bother with a beginner question.

Not a bother. Entirely appropriate (though sad that it is necessary).

    I don't see any .log file or any other idea where to start debugging.

1) Try make4ht --loglevel debug to get all output, as I understand it.

2) As for the lack of a log file, Michal will need to answer.  (Michal,
evidently the BasicTutorial should say something about how to proceed
with debugging. Errors are inevitable.)

    in to try to figure out what to adjust?

In the meantime, my suggestion is to run htlatex directly, per
https://tug.org/tex4ht. Then you will definitely see a whole lot of
output from TeX. It may or may not get you farther down the road, but
at least it won't just be silence.

htlatex file.tex "xhtml,html5,mathml,charset=utf-8" " -cunihtf -utf8"

(Or "mathjax" instead of "mathml", but that's far from your issue at the
moment.). --hth somehow, k.