Full details on how to set up your reseller account are available in the Reseller Startup Guide
CA Customers: http://www.hostpapasupport.com/go/ca/start-up-guide.shtml
US Customers: http://www.hostpapasupport.com/go/start-up-guide.shtml
EU Customers: http://www.hostpapasupport.com/go/eu/start-up-guide.shtml
AU Customers: http://www.hostpapasupport.com/go/au/start-up-guide.shtml
IN Customers: http://www.hostpapasupport.com/go/in/start-up-guide.shtml
MX Customers: http://www.hostpapasupport.com/go/mx/comenzando.shtml
Briefly: your cPanel will have a Reseller_setup package, by default. The limits are 1 MB disk space and 1 MB bandwidth: not enough to do anything!
Before you can create packages for clients, you must create one for yourself. Once this is done, then you may go to “Upgrade / Downgrade account” and assign that package to your control panel.
You may then use the same process to add client accounts to your WHM.
For additional information, this video tutorial will walk you through the process: http://hostpapasupport.com/tutorials/Tutorials_whm.shtml
If your account still isn’t working, you may open a support ticket: http://www.hostpapasupport.com/go/submit-ticket.shtml