One simple way is to stagger the start end times in the time range options in the attach to motion path options. Example: cube1 start 1 end 50, sphere1 start 5 end 55. Keep adding shapes by selecting the shapes you want and then the same motion path (curve). You can tweak the exact motions of each shape later by edting each shapes motionPath "U Value" in the graph editor. A tip to selecting multiple motion paths in the Outliner window display is to turn off "Dag object only" and scroll down to the motionPath nodes and select more than one there.