Cron set up

Is there anyone who can help me with the cron command?  I am clueless. I have tried reading several posts and have tried editing but having no success.  This is over my head.  

Charles. 

Is there anyone who can help me with the cron command?  I am clueless. I have tried reading several posts and have tried editing but having no success.  This is over my head.  

Charles. 

default dolphin cron setup:

cd /home/cpanel_username/public_html/periodic; /usr/local/bin/php -q cron.php

set for each minute. Attached is a screenshot for setting it up.