This script won't call the function, what do I do?

So, I wanted the script to call the function's ChangeTeam and Lobby but it won't call those two functions. I'm totally confused.

IntermissionTime = 10
RoundTime = 60
IntermissionString = "Intermission: %s" -- can be any string, put %s where you want the time to be displayed
RoundString = "Time Left: %s" -- can be any string, put %s where you want the time to be displayed

GetTime = Instance.new("RemoteFunction")
GetTime.Name = "GetTime"
GetTime.Parent = game.Workspace

function GetTime.OnServerInvoke()
    local T = {}
    table.insert(T, String)
    table.insert(T, CurrentTime)
    return T
end

function CountTime()
    while CurrentTime > 0 do
        wait(1)
        CurrentTime = CurrentTime -1
    end
end

function ChangeTeam()
	local currentPlayers = game.Players:GetPlayers() --Collect all players
    local currentTeams = game.Teams:GetChildren() --Collect all teams
    --Get a random player, and a random team
    local randomPlayer = currentPlayers[math.random(1,#currentPlayers)]
    local randomTeam = currentTeams[math.random(1,#currentTeams)]
    randomPlayer.Team = randomTeam
end

function Lobby()
	local currentPlayers = game.Players:GetPlayers() --Collect all players
    local currentTeams = game.Teams.BattleGofLobby --Collect all teams
    local Lobby = currentTeams
    currentPlayers.Team = Lobby
end

while wait() do
    String = IntermissionString
    Lobby() 
    CurrentTime = IntermissionTime 
    CountTime()
    String = RoundString
    ChangeTeam()
    CurrentTime = RoundTime
    CountTime()
end