Is this your first time to use WHM account ? if yes, here is the simple way how to manage your WHM account. The #1 guide is how to set your WHM Packages & Create new account.Go to your WHM account with use server ip addresses:
http://IPSERVER:2086

Enter username and password

Create a Packages
Go to Main >> Packages >> Add Package

Create a New Account
Go to Main >> Account Functions >> Create a New Account

Note:

Domain name should without http://, just put your domainname.com
Username must be not more 8 char / digit, just user auto create username after put the domain name
Do not Tick the DNS Settings, and use your local nameservers.