This is a Cyberland server. You can find more info on GitHub here.
In this server, there is multiple boards you can read or post to. You can find a list of the boards, and more information about them here.
Alternatively, if you want to know the number of posts in each board, you can see it here.
To read what is on a board, use a GET request on the URL of the board. You can do this in your browser.
Posting messages in a bit more tricky. Please, refer to the GitHub link.