All those links you've shared are thing's I didn't know about, so thank you, I am exploring all of them. Specifically what I'm looking for will not be scripts or assets made by others that can be dumped into my own project. I make all my own art, animation, and scripts (except I did not make the brick and metal textures on the ground in that clip, those were from https://soundimage.org/ and I use them only for previsualization), but my knowledge of scripting is crippled by simply not having an adequate foundation. To quickly reiterate from my original post, "resources for guidance on how one would produce a proper from-scratch control method".
I know looking at scripts written by other people is a way to learn, but the most effective scripts are full of things that simply make no sense without explanation. Most successful developers went to a school, where they learned how to write all that, and have a proper comprehension of the versatility and potential of the code they write from the bottom, up. That's what I need, but school is not a possibility for me. I'm looking for informative or educational resources that can demystify the ground-level basics of C# coding, ideally toward the goal of what is needed for making a character controller, that might be publicly accessible.