Shameless plug, but I wrote some blog posts because I had a lot of the same questions. In my case, I wanted to learn the WebGL APIs, so I wrote two posts:

* https://avikdas.com/2020/07/08/barebones-webgl-in-75-lines-o...

* https://avikdas.com/2020/07/21/barebones-3d-rendering-with-w...

I still go back to them myself to refresh my memory. It's funny that I called this a lot of boilerplate, but Vulkan is known to have even more.

This won't answer all your questions, but maybe it'll answer some of them.