To Create a cPanel account first login to WHM
(Home » Account Functions » Create a New Account)
Then Click Create New Account
Once you click create new account the following will appear fill in the information below to match your domain name.
For the Password we recommend a generated password
Once you have the above filled in you will have to select a package, if you do not have a package created you can make one by ticking "Select Options Manually"
Once you have those selected scroll down to the bottom and click create then your account will be created for you.