What subjects should I discuss in my community?

Hi there,
That varies. You can write a commentary for each product you suggest. You can add a subject for every main action or feature section if you also have a single big product, such as a mr whippy cart. You can add a subject or subjects for each type of user you have, such as end users, API developers, and WhatsApp developers.
Users can discuss subjects that don't quite fit into the other categories by opening General Discussion threads. You can keep an eye on this topic in case any new problems arise that call for more discussion.