First simple steps

Let's start!

See how simple it is.

First step is to install Unity (Get Unity).

Next is to start new project.

At last add new 2D Object to the opened scene. Rename it to Brick, add sprite to the newly created Sprites folder (Let's keep order from the beginning!) and then add this sprite to our Brick object. Change color and hit Play button. 

Notice that changes made in Play mode (i.e. changing shape or color)  are not saved in the editor.

We can simply duplicate object and change its color.