Can a 2009 Mac get iMovie?

High Sierra will run current iMovie 10.1.12. To confirm, go to the online app store, sign in with your Apple ID, search for the iMovie app and download it for free. If there is already a verion of iMovie on the computer you will first need to remove it because the computer was purchased with an Apple ID other than your own, and therefore you won't be able to update the old version. You can put it in the trash, but don't delete the trash, and then download the new vewsion.

I would do the above on the computer before you purchase the computer to verify that you can download the new version in case there is some unknown reason that prevents the download.

-- Rich

You should be able to get iMovie on the used Mac, but since I have never tried it with a computer bought used I can't say for sure. That's why I suggest that before you purchase your computer you try it out and see if the iMovie download is available.

-- Rich