There are several ways you can create holes and transparency in shapes. You can use the Opacity, Blend Mode, and Preserve Opacity parameters in the Properties Inspector to modify a shape’s overall transparency.
For more information on using object blending parameters, see Blend Modes.
You can use masks to punch holes inside shapes using the mask drawing tools. You can also apply image masks to a shape, which allow you to use any object to define transparency. For more information on using masks and image masks, see Using Masks to Create Transparency.