When you say you "set up" a domain, what do you mean? Did you add it to your local hosts file for local development? Did you add it to public DNS somewhere? In either case, what IP address is the domain pointing to? There's far too much missing information here to understand what you're trying to accomplish, let along why it doesn't work. If you are trying to make the server publicly available and you've pointed the host at the public IP of your server, and that public IP is either NAT'd through your firewall to your machine, and the ports are allowed, then it will work so long as you bind the CommandBox server to the public IP. Note, this is not the default behavior. By default, CommandBox will bind to localhost which will not be externally accessible. That's just now networking works.
Regarding Lucee's default password, this is solved very simply by using a combination of CFConfig and the dotenv module as I've explained here:
That said, I would recommend using an entire .cfconfig.json file for managing all of your configuration including your password and much more.
And finally, if this server is to be publicly accessible, make sure you're on the latest 5.2 release (which just came out this week) and make sure you use the security profiles to put CommandBox in production mode and make sure the admin isn't accessible externally for security.
Thanks!
~Brad
Developer Advocate
Ortus Solutions, Corp