How to use DataStore for Teams?

I would normally close this question, since it's more of a request, but I had a lot of issues finding a simple tutorial on data stores, as well, when I was learning. Some of the tutorials on the Wiki are really drawn out and, although the more complex examples lead to more effective data stores, it's neither necessary nor helpful for someone trying to learn.

The basics of a datastore are as follow. Through the DataStoreService, we use the :GetAsync() method to retrieve any existing data for the given key (unique or otherwise). When you want to save or overwrite pre-existing data, you use the :SetAsync() method. One of this method's arguments is the key that I mentioned. You could, for example, have a unique key for each player (ie Player.UserId .. "_Key").

Tying this all together, we can create a simple data store. In the example below, I'll create a data store for leaderstats.

Run through a ServerScript...

local DataStoreService = game:GetService("DataStoreService")
local Players = game:GetService("Players")
local LeaderboardData = DataStoreService:GetDataStore("LeaderboardData") --returns a GlobalDataStore, through which we run :GetAsync() and :SetAsync()

Players.PlayerAdded:Connect(function(Player)
	local SavedData = LeaderboardData:GetAsync(Player.UserId .. "_Key") -- retrieve entire table of saved data
	local leaderstats = Instance.new("Model")
	leaderstats.Name = "leaderstats"
	leaderstats.Parent = Player
	local Kills = Instance.new("IntValue")
	Kills.Name = "Kills"
	Kills.Parent = leaderstats
	local Deaths = Instance.new("IntValue")
	Deaths.Name = "Deaths"
	Deaths.Parent = leaderstats
	if SavedData then
		Kills.Value = SavedData[1] or 0 -- remember, we set the "Kills" value to the first table entry
		Deaths.Value = SavedData[2] or 0 --we set "Deaths" to the second table entry or 0 if nil
	end
end)

Players.PlayerRemoving:Connect(function(Player)
	local leaderstats = Player:FindFirstChild("leaderstats")
	if leaderstats then
		local Kills = leaderstats.Kills
		local Deaths = leaderstats.Deaths
		local DataToSave = {Kills.Value,Deaths.Value} -- place all data in a table, so we can save it all at once
		LeaderboardData:SetAsync(Player.UserId .. "_Key",DataToSave) -- give datastore a unique key and save table
	end
end)

Of course, you can create more complex, more secure data stores, which you would definitely want to look into if you were handling a popular game. You can find a simple tutorial to data stores here, and a more complex tutorial here

Good luck!

Note: be sure to enable "Studio Access to API Services" through your game settings before setting data stores!