To create a Shopify account, you have to go to the signup page, here.
You will have a page like this:
Once you have filled in your details, click on "Create an account". Finally, you will have this page and can start to create your first store:
Note: Shopify is the best CMS for e-commerce, so definetly create an account if you plan to open an online store or you wan't to sell using social media.
Need any further help? Contact us.