BASIC SHAPES

The starting point of 3D design is a primitive shape. These shapes can be added, subtracted, and combined with one another to build just about anything. The action of adding, subtracting, or combining primitive shapes is called a Boolean operation.
Here are some common 3D primitive shapes:
Cube
Cylinder
Tube
Sphere
Torus
Cone

The exciting thing about design, other than making your ideas real, is there are many different ways to combine shapes to make more complex things like this chair.

Since there are many ways to design, there is no 'right' way to do it. It's up to you, the designer, to figure out the best shapes to use, the best way to arrange the shapes and the the best order to group the shapes to create the shape you are looking for.

CREATING HOLES

Instructions:
Drag a blue Polygon shape to the workplane and place it in the area outlined in orange.
Did you know you can change any shape into a hole tool? Yep, you sure can!

Select the Polygon, by left clicking it, then select the Hole option in the Inspector window in the near upper right corner of the editor window.