We are using Theme my login free plugin for this theme. You can follow this plugin official documentation for details information.
You will be notified to install this plugin after active this theme. Once you active this plugin it will create the login, registration pages.
and if you import this theme demo data you will have those login, registration pages as well.
This theme has a custom page template for login registration pages. You may have to select that page template for those pages.
Just edit the page and select the login/registration page template from the template select dropdown.