We've actually recently required a hub, which is a super easy way to join games.
Simply put the following IP in your minecraft multiplayer servers list (add server, or direct connect): us.mcgamer.net
One there, you'll see a heck of a lot of people, and a heck of a lot of gamemodes. No need to worry though, simply navigate your way to the "Survival Games" section, and find a sign on the wall that reads "Lobby". Games in lobby are the games they you will join if you'd like to play, and games listed as "in-game" are for spectating currently occurring games.
Let me know if you need further clarification, or help
