I was able to successfully fork, update and make a pull request on a GitHub repository! For this self-taught programming hobbyist this is a "BIG DEAL!"
I followed the instructions about forking a repository using the octocat tutorial example:
https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/working-with-forks/fork-a-repo
Following that tutorial got me over the fear of screwing things up when I updated the HTML file with some Lorem Ipsum text.
So now I was ready to try doing an actual "fix" to a real repo.
https://github.com/Apress/beginning-cpp20
The official repo is missing some source code files for chapter 7, files that use import instead of #include.
Again, following the octocat tutorial I forked and cloned to local the repo. Added files/folders and tried to do an update to my repo fork, and was denied access!
After a bit of thought I believe adding the original repo as an upstream source was the cause. So delete my local repo and start the fork process again, this time NOT adding the upstreams.
And now I could update my GitHub forked repo and then add a pull request.
If/when the author(s) acknowledge the pull request will hopefully be simply a matter of time. Whether they accept my changes or not is kinda moot.
Now I feel like "I Are Programmer! Beep-boop-beep!"