How I make a Admin Script? Part 2

You already saved the ban when using that event. However, if you want to kick the player when he joins the player again you would try the following:

game.Players.PlayerAdded:Connect(function(plr)
         local Data
      local s, e  = pcall(function()
		Data = BannedPlayers:GetAsync(plr.UserId)
	end)

       if s and Data then -- if the request is successful and the data is valid.
              plr:Kick()
          elseif not Data then
                print("No data found")

           else
            error(e)
       end
 end)

Again, do your research on Datastores and Roblox server-client model because you seem to not understand it very well (from what I can see in the past replies),

yeah, im a starter dev i should have learned in developer hub

also here are the service im gonna use:

	--// Services \\--
local DSS = game:GetService("DataStoreService") -- DataStore Bans
local ReplicatedStorage = game:GetService("ReplicatedStorage") -- For RemotesEvents
local MessagingService = game:GetService("MessagingService") -- idk
local ServerStorage = game:GetService("ServerStorage") -- To get the GUIS
local TestService = game:GetService("TestService") -- If errors