All subscription plans that are toggled as available for purchase and not private will appear on your storefront when a customer goes to the join page. Without at least one subscription plan enabled your join page will not work correctly, so make sure you've enabled one.
The Join Page is one of the few pages where we don't allow code customization on. These pages need to remain secure for collecting login credentials and payment information so customization is limited on them.
All templates will have access to the join page via the main call to action button on the home page:
If a customer is browsing your catalog and sees a video they like:
The Get Access Now button will also bring them to a page that shows available subscriptions (and any bundles the video might belong to)