It looks like you recently set up the site naturegrace.wordpress.com. Is this the site you need assistance with?
If not, we can only assist you with sites hosted on WordPress.com. Our Premium plan is just for sites we host, not sites hosted elsewhere, and our domain mapping option is just to point a domain to a site hosted here, not for other WordPress sites.
If you want to point a domain to a site hosted elsewhere, you should find out from your hosting provider what information you need to give your domain registrar, and then update your registrar records accordingly. That will include either name server information or A records, but the process varies by hosting provider.