ID:1669514
 
(See the best response by Ter13.)
How do I give specific people specific things, for example if someone earns a custome costume for the game, or a unlockable. How would I give it for them, and just for them?

Best response
You would get a handle to that person's mob, then create the item, and put it in their contents.

There isn't much more information I can give you, because you haven't shown us any code for how your game works.