lobby/team based/round multiplayer?

Hey guys, I am looking to get some insight on the most practical way to do team and round based Multiplayer with a lobby before the match starts, for example, each game needs a certain about of players, and it will start once all the players have joined in the lobby... once all the players join, it starts the game, and creates each team, and then there is X number of rounds based off a timer.
Where would be the best place to start? I am know it's possible but I am curious to hear what the most proper approach would be from some of the experts, like @JohnTube.

Thanks!