To scale an object in your Scene
Make sure you are in the Scene Creator and not the Model Creator
Select the double ended arrow on the editor toolbar. This will put your object into scale mode
Select the item you want to scale by clicking on it, or selecting it from the object tree
You will see three lines which represent the three axis that can be scaled. This widget will be at the pivot point of the object. If you can't see the widgets, click and drag to look around the scene until you can see it.
When you hover over one of the coloured squares it will turn yellow. This means it is active and you will be scaling the object on the selected squares axis only
When you hover closer to the centre all three lines and the white squares will turn yellow. This means all three axis are active and you will be scaling the object uniformly
Click and drag to scale the object .
You can also enter specific values in the Transform section on the bottom right of the Properties menu