If you are experiencing issues when creating and setting up new nameservers in the cPanel environment, the following guides have been put out by our team which can help get you through this process:
https://docs.cpanel.net/knowledge-base/dns/how-to-set-up-nameservers-in-a-cpanel-environment/
https://blog.cpanel.com/how-to-create-your-own-name-servers/
If the primary domain that you will be using for your nameservers uses google domains, you will want to ensure that ns1 and ns2.yourdomain.tld have a proper A record pointing to the cPanel server IP.
Googles documentation on creating A records is linked here:
https://support.google.com/domains/answer/9211383?hl=en
You will then need to register the new nameservers with Google. Google calls this type of record a Registered Host record.
From the Google Domains main page, you click Manage for a given domain, then click the DNS tab on the left. There should be a Registered Hosts section on this page that will allow you to register the new nameservers.
Once your new nameservers have A records that point to the cPanel server, and the nameservers have been registered, you should be able to use those nameservers to hosting DNS for domains moving forward.