It's the weekend and and/or late at night for a lot of the people here.
You need to:
1. Go to your domain registrar and set up your domain to create nameservers pointed to your linode ips.
2. In whm go to "nameserver ips" (or something along those lines) and let it populate them automatically.
3. create dns records for the domains you want to host
4. set the nameservers for your domains to your private nameservers.
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Paid supportHow to ask for help
1. Give details of your problem
2. Post any errors
3. Post relevant logs.
4. Don't hide details i.e. your domain, it just makes things harder
5. Be polite or you'll be eaten by a grue