Finished making the lower plate:

• Used the sketch tool to make a sketch of a circle.
• Used extrude tool to make it a cylinder.
• Used fillet tool to make the edge rounder.
• Used the sketch tool to make a small circle near the edge.
• Used the extrude tool to use the sketch to make a hole in the lower plate.
• Then I used the circular pattern tool to make 6 identical holes proportional to each other.