Open QuickTime Player
Click File
Select New Movie Recording
Click the red Record button
Choose your camera and microphone if needed
Click the red Stop button when finished
Save the video file
Open Photo Booth
Click the Record Video button
Click the red Record button
Click the Stop button when finished
Save or export the video
Open the Screenshot toolbar with Shift + Command + 5
Select Record Entire Screen or Record Selected Portion
Click Record
Click the Stop button in the menu bar when finished
Save the recording when prompted