https://reticulum.network/start.html has an overview and how to connect.
There is a manual with a lot more information on how it works and the ideas behind it at https://reticulum.network/manual/ however it's quite large and not really a user friendly guide
If you just want to play with it https://reticulum.network/manual/software.html has a list of clients and software using it.
Chit-chat is one thing.