That’s basically how I did it.
To properly learn it using this method, create a directory that contains only text files and sub directories and treat it like a real project. Add files, delete them, play around with updating the repository. Try and go back a few updates and see how the things react. Since it’s not a real project there’s no risk of loss, but you’ll still get to see the effects of what you do.
My sibling ran into this issue once. I’m not sure if it’s a setting or a default, but vscode would assume they were working in a blank repo until they made a commit.
Sounds like this person had the project (without source control) in another IDE, tried out VSCode, and it assumed that it was all ‘changes’. I don’t use VSCode, do I can’t say for certain, but I know my sibling lost ~4 hours of project set up for the same reason (though they immediately realized it was their fault).