Okay so I am making a 2D and i want to know how to make it to where when you click on a cube you can move it
I am not vary fair into programing. and so I am stuck here i cant figure it out. 
You can use this function to be able to click on a gameobject, like a cube.
Then you just have to use the cubes transform to move it around.
This should get you started.
Okay thanks.