How do I Load and Save strings in Data Persistence?

Data Persistence can easily be called from the Player itself (Unlike Data Store where you have to call the service). Also remember that you should make a habit of using :WaitForDataReady(). This is very important to keep errors out of your script. Here are some examples:

game.Players.bbissell:WaitForDataReady() --Waits for the Data Persistence Service to be available.
game.Players.bbissell:SaveString("Nickname", "myNickname") --Saves the string to that player
print(game.Players.bbissell:LoadString("Nickname")) --Prints the saved string for that player

There is much more you can do with the Data Persistence service. Read up on it here.