What is the name of the domain?
ToolToSchool
What is the issue you’re encountering
Connect to Wordpress Nameserver
Welcome to the Cloudflare Community. 
If your domain is ToolToSchool.com, you cannot change the nameservers because the use of Cloudflare nameservers is a requirement of Cloudflare registrar. You don’t need to change your nameservers to use WordPress. Please review the following.