Drag an “Empty Actor” to the scene.
Set its location to 0, 0, 0
Click “DefaultSceneRoot” in the Details tab. Set “Mobility” to “Static”
In World Outliner you have to select everything in the scene except your Player. The easiest way to do this is filter by clicking ‘type’, that way the actor is top of the list. With everything select then right click and ‘attach’ to that empty actor.
Now when you adjust the scale and location of the empty actor it affects everything