How to make a person be in a team when he/she joins?

So I made a script and it turns out neat then i added a few lines then the player keeps on spawning in a team already.

ct = script.Parent.ClassHolder.CounterTerrorists
t = script.Parent.ClassHolder.Terrorists
ClassHolder = script.Parent
Teamjoined = false

function WaitTime()
    Teamjoined = true
    wait(600)
    Teamjoined = false
end

ct.MouseButton1Down:connect(function()
    if Teamjoined == false then
        game.Players.LocalPlayer.TeamColor = BrickColor.new('Really blue')
        game.Players.LocalPlayer:LoadCharacter()
        ClassHolder.Visible = false
        WaitTime()
    elseif Teamjoined == true then
        print'Error Wait Time'
    end
end)

t.MouseButton1Down:connect(function()
    if Teamjoined == false then
        game.Players.LocalPlayer.TeamColor = BrickColor.new('Really red')
        game.Players.LocalPlayer:LoadCharacter()
        ClassHolder.Visible = false
        WaitTime()
    elseif Teamjoined == true then
        print'Error Wait Time'
    end
end)

Here's also my problem. I want a player to join a team THEN he will have to wait for a couple of seconds before he/she can switch teams.