We do not provide nameservers with our service. You can either install and configure them on your VPS or can use a 3rd party DNS provider such as Amazon Route 53 or Hurricane Electric's Free DNS.
To configure your own nameservers with WHM/cPanel, simply go to your domain registrar and create sub nameservers such as ns1.yourdomain.com and ns2.yourdomain.com and point them to your VPSs main IP. After that, you can simply enter those values on your WHM/cPanel's first time setup wizard.
Also check https://vpsdime.com/knowledgebase/74_how-can-i-point-or-connect-my-domain-name-to-my-vps