Trying to use Sketchup

Here is my first attempt at using Sketchup to create a 3D model design. I struggled to use Sketchup (/am hopeless with computers) and grew impatient with it quickly. Throw in some terrible time management and not getting around to watching all the video tutorials, and voila - my model. But I got some helpful feedback in my class today, and am going to learn how to use it properly. Cool beans.

This is the section sketch it was based upon, using the words 'rhythmic' and 'flavour' for above and below. As you can see, the below ground part of the building doesn't really accurately depict what it was meant to because I'm a Sketchup rookie.