OK when I got my welcome email it said I could use their dns servers ns1.servermatrix.com and ns2.servermatrix.com . I already have custom name servers and I'm setting up my whm for the first time right now Can I set it to my custom name server name and just assign it an ip and be good to go after I change the ip at the registrar or do I have to do more than that? Can anyone give me the exact process?

Also when i try to assign it ips it says they already have ips should I just give it my first two ips of my server and register it at the registrar?