Help with universes?

How do I transfer data to one place in a universe, to another? A wiki link and/or a script example will work fine.

Example of what I am asking:

A player goes to a Universe, then teleports to a place. They do an obby, and then they teleport back. When they get back, they get a notification they beat it, and then a check appears on a GUI.

I don't need help with the GUI and stuff, just how to transfer that data.