How to save more than one data in one script?

Hello. You need the name of the dictionary's value. For example, instead of writing SavedGames.Value = Data you'd write SavedGames.Value = Data.Games. Try this:

-- services --

local DataStoreService = game:GetService("DataStoreService")
local SaveGameData = DataStoreService:GetDataStore("SaveGameData")

-- variables

local RemoteEvent = game.ReplicatedStorage.RemoteEvent

-- leaderstats

game.Players.PlayerAdded:Connect(function(player)

    local leaderstats = Instance.new("Folder", player)
    leaderstats.Name = "leaderstats"

    local SavedGames = Instance.new("IntValue", leaderstats)
    SavedGames.Name = "SavedGames"

    local OtherData = Instance.new("IntValue", leaderstats)
    OtherData.Name = "OtherData"

    -- getasync functions

    local PlayerUserId = "Player_"..player.UserId

    local Data
    local sucess, errormessage = pcall(function()
        Data = SaveGameData:GetAsync(PlayerUserId)
    end)

    -- setting data

    if sucess then
		if Data then
           	 SavedGames.Value = Data.Games
            	OtherData.Value = Data.OtherData
		end
else
	warn(errormessage)
        end


    end)

    -- when the player leaves do

    game.Players.PlayerRemoving:Connect(function(player)
        -- setasync functions

        local PlayerUserId = "Player_"..player.UserId

        local Data = {
	        Games = player.leaderstats.SavedGames.Value;
        	OtherData = player.leaderstats.SavedGames.Value;
    }

        local sucess, errormessage = pcall(function()
            SaveGameData:SetAsync(PlayerUserId, Data)
        end)

        -- if the data saved

        if sucess then
            print("Data saved sucessfully")
        else
            print("Data did not save because...")
            warn(errormessage)
        end
    end)

Please upvote and accept this answer if it helps.