Hi @Edward_Finkelstein ,
the errors are more related to git and GitHub than ROOT per se – you will find many good resources around the web about submitting pull requests.
As the first error message says, GitHub removed support for password authentication, and the blog post they link to has links that explain what to use instead and how to set it up (SSH authentication is probably the simplest to set up if you already use SSH).
You can create your test repository on GitHub and try things out with it, e.g. you can try opening a PR and merge changes into your own test repo to practice the workflow, it’s anyway good to learn because it’s how most open source software gets developed these days.
Cheers,
Enrico