Let's start with some essential techniques...
To open up some additional screen space, collapse the Output bar by clicking the Output Bar button:
To rotate the model, press Shift and the middle mouse button, and move the mouse:
To zoom, roll the scroll wheel:
To pan (move), hold the middle mouse button, and move the mouse:
To see the occupant, hide the wall part and then the air part. To do this, position the curser over each, hold Ctrl and click the middle mouse button:
Hide the wall:
An alternative way to hide parts is to left click, and click the Hide icon from the context toolbar:
Hide the air:
Now we can see the occupant!
To show all the parts, press Ctrl and middle click off the model in the graphics window:
Alternatively, left click, and click the Show All icon:
In the next steps, we use these techniques to navigate the model and to control part visibility.