How do you determine what executable and DLL’s a C# Visual Studio project produces?

This will depend on the project type you are creating but for the most part the "name" of the project is used to name the DLL, EXE, etc. that is produced by Visual Studio.  You can change this after the fact by going into the project settings and changing the Assembly Name entry on the Application tab.
To see what is produced when you compile you can right-click the project in the solution explorer and select Open Folder in Windows Explorer and then navigate into the bin folder to see the files that are produced when compiled.

In your project folder, go to Bin and then Debug or Release folder depending on your build option. The default is Debug. You will see your DLL or EXE there.