How to change the player's team using script?

Well, a player object has a property called team, which can be assigned instead of assigning a team color . One thing you did wrong in your code is that you tried to set the team of the Player's humanoid to that team, not the actual player itself.

With that said

Here is the fixed code(revamped version)

local part = script.Parent
part.Touched:Connect(function(hit)
	local plr = game.Players:GetPlayerFromCharacter(hit.Parent)
	if plr then
		print("Changed Player's Team")
		player.Team = game.Teams.LevelTwo
		hit.Parent:BreakJoints()
	end
end)

In this answer, I used the GetPlayerFromCharcter function of the players service, which returns a player when given a character, or it returns nil if the character parameter isn't a character.

game.Players:GetPlayerFromCharacter(instance Character)

References

• player object

• team property

• getPlayerFromCharacter function

Note that the Team property does not replicate across the client-server boundary, therefore it cannot be used in local scripts