Open Finder, click on Applications, and locate "Photo Booth" (or use Spotlight search by pressing Cmd + Space and typing "Photo Booth").
So Lena opened her laptop and stared at the tiny dot above the screen. The camera. how to take a picture on computer
If you have an external webcam, click the "Change Camera" icon (top right) to flip between cameras. Open Finder, click on Applications, and locate "Photo