This project is going to take advantage of several powerful editing tools that Bender provides. The first one is going to be the
extrude operator. Extruding takes its name from a process for making things in real life, but in 3D modelling, extruding takes a selected part of an existing model and creates new geometry on the edge of the selected parts, so that the original can be moved away but remain attached to where it came from. The result is a new shape that can then be edited.
Let's get ready; it's time to get to work: