Help with python not recognized

So I'm pretty new to coding, and I recently learned IDLE isn't ideal to use, so I got Atom. Trying to get it work, got " python ' is not recognized as an internal or external command, operable program, or batch file," tried the fix found [here](https://github.com/rgbkrk/atom-script/issues/166) (specifically [this](https://github.com/rgbkrk/atom-script/issues/166#issuecomment-49495061)), which didn't fix it and now IDLE isn't working either. I'm not really sure what happened or what the setx did, so if you could maybe point me to something that explains what's going on that'd be great.