can i create the domain once i have the control panel? or do i need to get a domain from another company before i get the control panel?

Please elaborate?

If you are saying that you subscribe to a hosting account, you do not need to have a domain name to start things up. You can always purchase a domain somewhere else(if your hosting company allow) and change the domain info of your account accordingly from the host's control panel.

I hope this might help. Hopefully didn't answer the wrong thing.

Usually it is better to register a domain name before you have access to the control panel because a domain name to propagate properly will take anything upto 72 hours.