If you’ve bought a domain from GoDaddy, you must reconfigure your DNS settings to point the domain at your Shopify-hosted storefront.

Before you begin

Before you follow these instructions, you should be familiar with the general procedure for modifying your DNS settings.

You can also read Understanding domains if you’re not familiar with the concepts and terminology used here.

To set up your domain with GoDaddy

1. Login to your GoDaddy account at https://mya.godaddy.com/.

2. In the DOMAINS section, click *Manage.

3. Click the settings icon for your domain:

4. Click Manage DNS.

5. Click the Edit Record icon.

6. A dialog window opens. Change the Points to: field to Shopify’s IP address: 23.227.xx.xx

Click Finish.

7. Scroll down to the CName (Alias) section.

8. Click the icon for the Edit Record button on the line of the “www” host

9. A dialog window opens. Change the Points to: field to point towards sub.yourdomain.com (replace YourStoreName with your actual .myshopify.com store name). For example:

Click Finish.

10. Click Save Changes in the action needed bar.

After you’ve claimed your domain, it can take up to 48 hours for changes to take effect. You can check the status of your domains here to see if the changes have been applied.

If you are not able to edit your DNS records from within your domain provider’s Admin section, it’s likely that you have your domain’s nameservers pointed to a third party. To resolve this issue, you must contact your domain provider to have them point your domain’s nameservers to their default nameservers.

Via: https://docs.shopify.com/manual/settings/domains/third-party-domains/popular-providers/godaddy