There's three different views of your home feed.

Subscribed

This is a feed that contains all the posts across all the communities you are subscribed to. You can be subscribed to any community inside the paradisus instance or any other instance in the fediverse.

All

This is a collection of all paradisus user's subscribed feeds together. In some ways, this is a summary of what all paradisus users are interested in.

Local

This feed contains all paradisus communities.

How to Subscribe to an Instance outside Paradisus

In short, the "All" tab shows all subscribed communities across all users. Because there are only a few users on this instance, there won't be that many feeds available just yet! You'll need to go out and explore communities and subscribe to them. Then the community will appear not only in your subscribed feed but also the all feed for everyone in paradisus.

Praise the sun!