As you can see in the image I created a blank project, added a script with a Debug.Log in Update (yes, the file is saved), and nothing is being printed to the console when i start the game.
It looks like you’re running a full build (IE. File → Build & Run). Its in a separate window and the play button isn’t depressed in the editor. That runs the executable independently from the unity editor. To use the editor console you have to run it within the editor. The play button above your scene viewer will allow the console to work.