How do I save what Team a player is on?

Use DataStore silly :

local DataStoreService = game:GetService(“DataStoreService”)
local DataStore = DataStoreService(“DataStore”) -- Name this whatever you want

local function loadStarterData(Player) -- Basically this is the function that creates the stats
      local leaderstats = Instance.new(“Folder”)
      leaderstats.Name = “leaderstats”
      leaderstats.Parent = Player

      local Cash = Instance.new(“IntValue”)
      Cash.Name = “Cash” -- Name your currency
      Cash.Parent = leaderstats
end

local function loadData(Player) -- Function that loads the data
      local Data
      
      local s,e pcall(function()
             Data = DataStore:GetAsync(“UserId:”.. Player.UserId)
      end)
      if s then
            Player.leaderstats.Cash.Value = Data[1]
            Player.Team = game.Teams[Data[1]]
            print(“Loaded ”.. Player.Name ..”’s data successfully”)
      else
            print(“Failed to load ”.. Player.Name ..”’s data”)
      end

end

local function saveData(Player) -- Function that saves the data
      local Data = {
         Cash = 0,
         Team = “”
       }
      
      Data.Cash = Player.leaderstats.Cash.Value
      Team = Player.Team.Name

      local s,e pcall(function()
             DataStore:SetAsync(“UserId:”.. Player.UserId, Data)
      end)
      if s then
            print(“Saved ”.. Player.Name ..”’s data successfully”)
      else
            print(“Failed to save ”.. Player.Name ..”’s data”)
      end

end

game.Players.PlayerAdded:Connect(function(Player)
       loadStarterData(Player)
       loadData(Player)    
end)

game.Players.PlayerRemoving:Connect(function(Player)
       saveData(Player)
end)