Build an access application function in a Shopify site

RE: Build an access application function in a Shopify site - All pages require login to access. - Users can either sign in or apply for access. - Sign in requires username and password (default from Shopify) - The application requires a to-be-determined list of form fields (i.e. name, email, phone, business name, etc.). - Upon submission, admin gets a notification to review and approve the application. - Upon admin approval, the user is notified and asked to create a password. - Upon password creation, the user gains access to the webpages.