How to use remote events that changes the text label?

So I am making a Minigame and I want a text lable to change at the top of the screen using remote events and also going through the PlayerGui.

MAIN SCRIPT: I am using OnServerEvent would that be correct?

local maps = Repstore.Maps:GetChildren()
----------
--Events--
----------
local Rep = game:GetService("ReplicatedStorage")
local remote = Rep:WaitForChild("MainT")

remote.OnServerEvent:Connect(function()

end)
	while true do
		if game.Players.NumPlayers > 1 then
		for i, v in pairs(game.Players:GetChildren()) do
			local pgui = v:WaitForChild("PlayerGui")
			pgui:WaitForChild("MainText").TextLabel.Text = "Not enough players to start!"
		end
		else
			wait(2)
			for i, v in pairs(game.Players:GetChildren()) do
			local pgui1 = v:WaitForChild("PlayerGui")
			pgui1:WaitForChild("MainText").TextLabel.Text = "Chosing map"
			wait(3)
			ranGame = math.random(1, #maps)
			gameChosen = maps[ranGame]
			for i, v in pairs(game.Players:GetChildren()) do
			local pgui2 = v:WaitForChild("PlayerGui")
			pgui2:WaitForChild("MainText").TextLabel.Text = "Map chosen: ".. gameChosen.Name
			wait(3)
			gameChosenClone = gameChosen:Clone()
			gameChosenClone.Parent = game.Workspace.MapSelected
			wait(3)
			spawns = gameChosenClone.Spawns:GetChildren()
			for i,v in pairs(game.Players:GetPlayers())do
				name = v.Name
				check = game.Workspace:FindFirstChild(name)
				if check then
					checkHumanoid = check:FindFirstChild("Humanoid")
					if checkHumanoid then
						check:MoveTo(spawns[i].Position)
					end
					end
					end
					end
			end
				for i, v in pairs(game.Players:GetChildren()) do
					for i = 3, 1, 1 do
			local pgui3 = v:WaitForChild("PlayerGui")
			pgui3:WaitForChild("MainText").TextLabel.Text = "Game begins in".. i
				wait(1)
			end
			
				for i, v in pairs(game.Players:GetChildren()) do
					for i = 10,1, -1 do
			local pgui4 = v:WaitForChild("PlayerGui")
			pgui4:WaitForChild("MainText").TextLabel.Text = "Time left ".. i
				wait(1)
				end
				end
			end
			for i, v in pairs(game.Players:GetChildren()) do
			local pgui5 = v:WaitForChild("PlayerGui")
			pgui5:WaitForChild("MainText").TextLabel.Text = "Game ended"
			wait(3)
			for i, v in pairs(game.Players:GetChildren()) do
			local pgui6 = v:WaitForChild("PlayerGui")
			pgui6:WaitForChild("MainText").TextLabel.Text = "Giving the win to players who won!"
			for i, v in pairs(game.Players:GetPlayers()) do
				inGame = v:FindFirstChild("InGame")
			if inGame then
				v.leaderstats.Wins.Value = v.leaderstats.Wins.Value + 1
				v.leaderstats.Coins.Value = v.leaderstats.Coins.Value + 50
				end
				end
			end
			gameChosenClone:Destroy()
			
			for i,v in pairs(game.Players:GetPlayers())do
				v:FindFirstChild("Humanoid").Health = 0
			end
		
				for i, v in pairs(game.Players:GetChildren()) do
					for i = 60,1, -1 do
			local pgui4 = v:WaitForChild("PlayerGui")
			pgui4:WaitForChild("MainText").TextLabel.Text = "Intermission ".. i
			wait(1)
			
			end
			end
			end
		end
		wait(1)
		end

LOCAL SCRIPT: Should I use FireServer? or somthing else? OR Should i do remote.FireServer()

local Rep = game:GetService("ReplicatedStorage")
local remote = Rep:WaitForChild("MainT")
----------
--Player--
----------
player = game.Players.LocalPlayer
remote:FireServer()