If this is a fresh installation where you just unzip or untar the WordPress package, it’s normal you don’t find the wp-config.php. you should only find a wp-config-sample.php
The wp-config.php file is only created when you start the installation process through your browser. this process create the wp-config.php with the information you put in the installation process forms.
Now if you want to configure your WordPress installation without following the installation process through the browser, you have to copy (or rename) yourself the wp-config-sample.php to wp-config.php and then set the parameters in this file.