You're on a kbin instance, and it is the main one so most of them are probably already there. If any of them is not, just click the search button at the top of the screen and enter the name you see above without the ! and without the space before the @. e.g. "[email protected]", your instance will then look it up and subscribe you to it if found.
It might take a while for threads to begin to appear if it wasn't already there though.