iMovie*** (Apple Only)

iMovie is good for simple video edits; and it is free on Mac and iOS devices.
There are two tricks for exporting vertical video, such as for Instagram or Tik-Tok; either first import it as sideways video and edit it sideways; then after export, open it in QuickTime and rotate it. The second way is to start a new iMovie project as an “App Preview”, and make sure your first piece of timeline content is vertical video. The App Preview does have some limitations, such as with captions.