Install ubuntu studio linux https://ubuntustudio.org/ it has video, sound, image etc editing apps. Then search youtube for those app names, there is tutorial videos how to use those apps.
I'd suggest you to learn the basics from YouTube and if you'll get into it - get yourself an online course from skillshare or udemy for more advanced stuff. Good luck buddy :)
that depends on which software you want to learn to me i think you can start with Filmora then filmora pro after that go with adobe premiere pro. However you can start with any.
