Whenever i'm in studio mode the gui is centered as of the studio screen but it isn't in actual play mode then it is up in the top left corner.. help?
Set your GUI to .5 in position, if I am not mistaken, that should put it at 50% of the screen.
That's because the Explorer UI and Properties UI get actually subtract from the screen space, but screen space actually exists behind it.
You should try just experimenting with the Position of the Gui, and then close the Explorer and Properties and see if it looks centered. If not, then reopen it and experiment some more.
There is no set position for the Gui to be centered on, because it all depends on your Gui's Size.