Create the two teams using team.SetUp
At PlayerInitialSpawn hook, start a timer with two minutes (prepare timer) timer.Create (or timer.Simple). Only do this if the timer hasn’t already started (Do some variable checks). Also set the player to Team A.
When the timer reached 2 minutes, respawn all players, give them weapons, except one or a few which gets turned into Team B, spawn them somewhere else.
At PlayerDeath hook, see if the killer (variable 3) was in Team B, and Victim (variable 1) was in Team A. If so, set the players team to B and respawn him.
At the same hook, check how many players there’s left in Team A, if Team A is empty, restart the round/server.
Might need some additional check at PlayerInitialSpawn to prevent the player from spawning if the game is already running (?)
Hope this helps, ask again if you need anything.