iMovie

You can obtain the highest version of iMovie that Catalina will run, provided that you have, or ever have had, an earlier version of iMovie 10 on your Mac. Use the procedure described below. Otherwise, unfortunately, you will not be able to get iMovie 10, except possibly through unauthorized websites that are not recommended for safety reasons. Or possibly you could copy iMovie 10 over from another owned Mac.

To update/redownload iMovie 10, drag your iMovie 10 app from the Applications folder into the trash, but do not empty the trash. (You can skip that step if you had iMovie 10 on your computer before, but deleted it.) Sign in to the app store and open your purchases folder by clicking on your name at the bottom of the app store side bar.   You will see your purchases displayed, including iMovie 10. Redownload/update iMovie from there. If not successful, drag your present iMovie app out of the trash (if you moved it there) and return it to the Applications folder.

-- Rich