From Scratch?

Hello ??

I’m currently designing a theme for a non-profit organizations WordPress site that I’m 100% responsible for. I’ve been reading some of the information I’ve found here thus far but I’m not quite sure I have found exactly what I’m looking for. I’m hoping someone here would be kind enough to point me in the right direction.

I have read that the easiest way to create your own theme is by creating a child theme of one you particularly like. But …

What if I don’t want to do that? I want to create my own theme without having to do that so where do I get the vanilla core files or code that I need to add to pages/insert in newly created pages?

I hope this made sense.

I’m not sure if it would be needed but the privately designed/owned theme is located at: https://crr-fanclub.org/site/

Thank you for any help offered. I truly appreciate it.

PS: This is the first time ever in designing a WP theme for me!