To use your own domain name for your new grocery website, changes must be made to your domain name services (DNS) records. The person who registered as your domain name administrative contact, or the technical contact is authorized to make the needed changes.
The article that describes the general DNS settings can be found here: DNS Settings Guide
If you use GoDaddy as your domain registrar, refer to the following article for specific instructions on the needed DNS changes: GoDaddy DNS Setup Guide
DNS basics and terms can be found here: DNS Basics and Terms