in what file are username and password located

When I link to https://www.my-domain-name/wp-admin I’m prompted for username and password. The only such I’ve used creating the site aren’t recognized. For example, those used to create the MySQL database which are now in the wp-config file. In which file(wp-login, etc.) and precisely where in that file are the username and password for which the program tests? Knowing that, they have to work in the aforementioned prompt since they’re the values the code tests for.

Also, in what file is my email address?

Anyone? Thanks.