Setting up your domain is not something you have to do often, but it’s important that you do it properly the first time.
You manage all your domain settings on the Domains page in your Shopify admin:
A domain is the URL, or the website address, where your customers go to find your store online. Understanding how domains work is not an easy task, but there are only a couple of main points you need to know to set up your custom domain.
If you don’t have a custom domain name yet, buy your domain through Shopify. When you do that, you won’t need to configure your domain’s A name and CNAME records — Shopify will do it for you.