Use SOLID to improve the best practices to better your code, can to show hard, but with practice after will be easy.
- The first is a wrong project, isn't wrong but not to use good practice, there is an unique file with all the code there.
- The second one is a good project, it use the SOLID practice
To run these projects is necessary have the .net core installed and open the project.
$ dotnet restore
$ dotnet run