Only one possible implementation is shown! Just because it looks like this with me, it does not have to look like this with you
The examples show only a rough structure. Often they are partial solutions and not 100% solutions!
You can find the complete project in the sample project.
General Tips
The sample Minecraft project shows you how commands or events work. Not all options are described in the sample project. You can get more in-depth information further in the documentation.