Split a single video into as many clips as you like with Apple's Quicktime app. After you split a movie into clips, you can even rearrange them.
Video: Splitting a video in Quicktime
In the QuickTime Player app on a Mac, open the video you want to split into clips, then choose View > Show Clips.
Move the playhead (the red vertical line) to the place where you want to split the clip (or use the Touch Bar), then choose Edit > Split Clip.
The video splits into two clips. Repeat until you have as many clips as you want.
When you’re finished, click Done.