While not nearly as featureful as say OpenShot or Kdenlive, Avidemux is an open-source video editor that is simple to use and has been around for a long time. Avidemux 2.8 is now available as the latest feature release.
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I used to edit with Shotcut, but kdenlive is so much better!
You just need to watch 2 minutes tutorial on YouTube for the first use, and you will basically use only two keyboard hotkeys: S to select and X to cut.