Free, public domain, and royality free photos and video clips: http://mudesign.net/resources.html

iMovie alternatives
movavi - free and paid versions - both PC and Apple
https://www.movavi.com Download from your app store

DAVINCI RESOLVE
https://www.blackmagicdesign.com/products/davinciresolve/

Adobe Premier
https://www.adobe.com/products/premiere.html

Apple Final Cut Pro
Download from Macr App Store