Adding Subdomains : 

Subdomains can be added to your domain name by using the subdomains feature inside your Cpanel control panel. Simply login to your Cpanel using your web hosting information. Click on the Subdomains icon and follow the steps below.

Step One   Choose the name of your subdomain something.mydomainname.com  (replace the something with your subdomain choice. and mydomainname.com with your actual domain name.

Step Two   Choose the address you want this subdomain to redirect too.  Click Create Subdomain

Creating a subdomain also creates a folder with the same name in your public_html directory.

Setting your redirect on Step Two to this newly created folder is how you make the subdomain work with the newly created folder.

Subdomains need to settle online.  Just like a domain name. It can take 2-24 hours for a subdomain to settle on the net.

Your domain name must be working for a subdomain to work. If your domain is not working Click Here