HTML and CSS are all you need to build a website. This statement was true 20-something years ago, and it still gets said today, but it's starting to look less true when you look closely at many websites- even personal ones. Navigation menus that stay the same on every page using SSI or PHP, (neither of which Neocities supports,) blogs made with CMS's or SSG's- even with my own little art gallery, I use a set of janky, homemade shell scripts to make it.
While some people (me) may be eager to learn a bunch of new technologies in order to build a site exactly to their liking, not everyone is looking for that. Some people may just want to make a website for their non-tech-related hobby/interest/art/story/life and don't want to spend hours learning new ways to make their site more and more complex.
I think that statement is still true today. I think that, even if you can't make everything in exactly the same way, you can still make a worthwhile and perfectly usable site without server-side scripting, static site generators, JavaScript, or even janky shell scripts. The first settlers of the Web sure didn't have any of those things! (Well, they probably had their fair share of janky shell scripts.)
This section will have some tutorials on how to make certain common site features in a way that doesn't use any scripting or automation- just pure HTML and CSS. I will be assuming you already know basic HTML and CSS, though.
Now I'll note that I'm not super experienced in making websites, and I'm even less experienced in making tutorials, so I can't guarantee this will be perfect, or even all that helpful. If you have any suggestions, corrections, etc. to make, I'd be thrilled if you were to send me an e-mail.