What is the most logical next event?

How to create contour lines using sketchup
Click on the add imagery icon.
Go to wherever you want to get your contours from in the screen that comes up.
Draw a rectangle that is the size of the contours that you are creating.
Click on the move tool and holding down ctrl and make a copy and make sure it is directly above the previous layer. Type in the number that you want for contour lines.