I spent the last week doing exactly this after going over a decade without making a web page and having never done anything java related. The key thing for me was finding an existing website i liked that was hosted on github pages and used that as a template/example to see how things fit together. The learning curve at the very beginning was brutal, but once you get a few toeholds and can iterate things quickly start falling into place. The problem with the textbook approach is you don't know what you can skip until you already know it.
Most stuff getting slung around, as the parent mentions, is rooted in the kind of development that relies on NPM-adjacent tooling. The two things you mention (Java and modern Web development, especially something modelled after another thing found on GitHub Pages) tend to be miles apart in this decade. Where does Java come in to it?
He may mean JavaScript not Java. I get a lot of we newbies asking referring to Java when they mean JavaScript. Especially when in the context of web development.
For the parent: Java is completely different to JavaScript - the similarity is an accident of marketing and an original vision of the Web (in which most code was written in Java not JavaScript.)
The problem with this is that sometimes a good tutorial gives you insight on how they do things in the language/framework way.
If I pick up something new and just try to piece things together using a sample project or whatever, I tend to think in ways from the most familiar language I work in.
Also without familiarity, you can’t judge if the sample you picked is super opinionated or does things in a weird way.