"make a stage and rebirths leaderboard stat. make a datastore for stage and rebirths that saves and loads the player's stage and rebirths. change the player's stage when they step on a part of the same name in the Checkpoints folder"

-- server script

-- Get the DataStore
local DataStore = game:GetService("DataStoreService"):GetDataStore("StageAndRebirths")

-- Get the Checkpoints folder
local Checkpoints = game.Workspace.Checkpoints

-- Get the Players folder
local Players = game.Workspace.Players

-- Create a function to save the player's stage and rebirths
local function savePlayerData(player)
	-- Get the player's leaderstats
	local leaderstats = player.leaderstats
	
	-- Get the player's stage and rebirths
	local stage = leaderstats.Stage.Value
	local rebirths = leaderstats.Rebirths.Value
	
	-- Save the player's stage and rebirths
	DataStore:SetAsync(player.UserId, {Stage = stage, Rebirths = rebirths})
end

-- Create a function to load the player's stage and rebirths
local function loadPlayerData(player)
	-- Get the player's leaderstats
	local leaderstats = player.leaderstats
	
	-- Load the player's stage and rebirths
	local data = DataStore:GetAsync(player.UserId)
	if data then
		leaderstats.Stage.Value = data.Stage
		leaderstats.Rebirths.Value = data.Rebirths
	else
		-- Set the player's stage and rebirths to 0 if there is no data
		leaderstats.Stage.Value = 0
		leaderstats.Rebirths.Value = 0
	end
end

-- Create a function to change the player's stage when they touch a checkpoint
local function onTouchCheckpoint(part, player)
	-- Get the checkpoint's name
	local checkpointName = part.Name
	
	-- Get the player's leaderstats
	local leaderstats = player.leaderstats
	
	-- Set the player's stage to the checkpoint's name
	leaderstats.Stage.Value = checkpointName
	
	-- Save the player's stage and rebirths
	savePlayerData(player)
end

-- Connect the Touched event to the onTouchCheckpoint function
Checkpoints.ChildAdded:Connect(function(part)
	part.Touched:Connect(function(otherPart)
		if otherPart.Parent:FindFirstChild("Humanoid") then
			onTouchCheckpoint(part, otherPart.Parent)
		end
	end)
end)

-- Connect the PlayerAdded event to the loadPlayerData function
Players.PlayerAdded:Connect(loadPlayerData)