Cal here from Shopify, thanks for reaching out to us. Have you just purchased this domain from Shopify, or have you connected a third party domain?
When did you purchase the domain? What is the domain, and I'll take a quick glance from our side here? If it is a freshly purchased domain, the SSL may be pending for up to 48 hours, but usually resolves itself faster.
If you are finding that the SSL certs haven't been provisioned within 48 hours, we can attempt to reprovision them here.