You can find a products nameservers listed in your client area under that specific product. You should have also received an email containing all your important account information, including where to access your cPanel, your temporary FTP information, nameservers and more.
What are Nameservers?
Every site on the internet resides on an IP address. What if you had to remember a sequence of numbers instead of mysite.com? That would be difficult, right? Instead of remembering numbers, we just have to remember a domain name. And nameservers direct visitors to your Domain Name Server to make that possible.