I recognize this might not help you, but my first one was one of those huge Unleashed books "HTML and CGI" <https://books.google.com/books/about/HTML_and_CGI_unleashed....> which it seems one can still buy for $5
My first real web job out of collage was introducing HTX/IDX[1] to a shop that was still using Visual C++ to make CGI because C++ was the only hammer they had in their toolbox :sob:
1: I'm actually shocked that they still serve documentation for it https://learn.microsoft.com/en-us/previous-versions/iis/6.0-...