How do I make a copy of WordPress to other folder

If you want to move wordpress you should this: http://codex.wordpress.org/Giving_WordPress_Its_Own_Directory

I guess you want to create a development environment, and because you never edit core files of WordPress you don’t have to copy WordPress itself because the only thing you are changing is the theme folder. And you don’t want to install WordPress a second time in a sub-directory so maybe you should try creating a sub-domain: http://semperfiwebdesign.com/blog/setting-up-a-wordpress-development-environment-on-your-hosted-server/