The config file is empty until you install the script, once you install the script it should get filled in with your site's information. If it hasn't then the site you're using as a host might not be able to write the file. Unfortunately the config.php will be unique to your site as you need to fill in your own info.
You could try, anyway. Make sure you open it and fill in your own info in the spaces.
This is what the filled in one should look like: