Select a single object (art, text or photo) on your project by simply placing your cursor on the object and clicking once.
When an object is selected, a selection border will appear around it.
If the selection border is a thick pink border, this indicates that the object is locked. You cannot move or re-size a locked item.
If the selection border is green, has the four corner marks and rotation handle (see below), the object is unlocked and able to be moved, re-sized and rotated.
Select multiple objects by first selecting one object, then with your SHIFT key held down, click on the other objects you wish to select. You will see the selection border expand to include the other objects. The objects selected in a group can then be moved and re-sized as a group, as long as they are unlocked.