Domain Settings are found in the Online Store section.
Access: On control panel menu go to Online Store > Domains
Manage your domain names
If you just signed up for Shopify, you are using a Shopify hosted domain name.
Shopify will display your store’s domain name and give you options to:
2. Connect to an existing domain or transfer domain
3. Buy a domain
When your store is ready for launch, it is recommended you use a custom domain. .com or .ca domain names are most common in Canada.