Two copies of the website – one in root and one in subdirectory?

I am running this on a cpanel.
I have a root directory with a functional WordPress website, and I have created a subdirectory in the root to have a second live copy of the same website, but in a different language.

I have tried to find a step-by-step guide, but no one seems to be doing that. People either want it for testing, or want to move it from one directory to another.

I was wondering if someone could do some handholding, as I am not very savvy at this.