https://support.apple.com/en-us/HT208721
Use Shift-Command-5 in macOS Mojave
With macOS Mojave, press Shift-Command (⌘)-5 on your keyboard to see all the controls you need to record video and capture still images of your screen. Use these onscreen controls to select whether to record the entire screen, record a selected portion, or capture a still image of your screen. If you haven't upgraded to Mojave, you can record the screen with QuickTime Player.
iMovie is a great video editor that’s included with macOS and iOS. If you don’t have iMovie on your Mac, you can download it from the Mac App Store. Once it’s installed, you’re ready to add music to your video clip.
http://www.fromtexttospeech.com/
