The best way to describe CPanel is to imagine it as the system administrator for pretty much everything about your website and server. It will manage certain aspects of your domain, your emails, as well as a file manager where your WordPress website is stored and viewed by the world.
You will be able to log in to CPanel by going to yourdomain.com/cpanel. When you signed to our hosting package you will have received your login details by email. Alternatively, you are able to see them on your hosting dashboard.