The value is invalid. I can’t say exactly what is wrong without seeing the URL, but the error message tells me Git thinks it’s supposed to use an SSH connection to the host
https:. Using SSH is a good choice, but
https: isn’t even a valid hostname, let alone one for GitHub. The easiest thing to do is to find the correct URL from your repository page (the green “Code” button). Once you have that, you can set the URL like this:
git remote set-url origin URL_HERE
When you set up Git on a new computer or user account, you need to tell it who you are, see Git - First-Time Git Setup. That’s where the second error message comes from. If you already made commits there anyway you may need to fix the author information there.