This video also walks through this, if these instructions are hard to follow.
A set of demo games that each introduce new concepts, and the accompanying code. In each case, play through the demo and read the code, to understand what is happening and how it's done.
In the code files, the text in bold is the title of a passage, and the following text is what the passage contains.
Try to duplicate each of the demos in order, but feel free to experiment and modify things! Ask me, either in person or via email, if you have any questions.