This workshop is intended to be used as a tool by an instructor working with those interested in learning to program in C#. As such there are some gaps where there is assumed knowledge or a mentor ready to assist. For those going solo, Google is your friend.
Start by opening the Word document under the "docs" folder and follow the instructions for installing Visual Studio 2017 Community Edition and start the lessons. The rest of the files here excluding the .md files are the C# Workshop source files. By reviewing the Commits you'll see every lesson is a changeset that you can compare with your code if you run into any problems.
You'll be introduced to Visual Studio, an integrated development environment (IDE), which is where you type and compile your code. You could use notepad and other tools, but I prefer Visual Studio. This workshop heavily promotes unit tests. Introductory discussions on design patterns including repositories are brought up, though nothing in-depth.
Once you reach the object-oriented programming (OOP) descriptions, don't worry if you don't get it right away. Continue with the workshop and slowly you'll come to put the pieces together. This section is by far the hardest concept for new developers to grasp, so don't despair. There are plenty of WIKI articles on the web that can further assist you. The key point for this workshop is to keep doing the workshop as doing it helps you get to the AHA moment where everything comes together.
If for any reason the installation instruction or extensions don't work as expected, please realize that these tools change very frequently. A quick search on the web will usually help you find what you need. Always try the StackOverflow articles first as they are usually more relevant and on point.