80 yr old needs video editing advice
A local photo shop digitized some very old VHS tapes, saving them to my Seagate Portable External Hard Drive (not SSD). At my request, each VHS was saved as both .MOV and MP4. After connecting the Seagate to my iMac M1 (16GB) desktop/Sonoma, I was able to 'see' the various .mov and mp4 digitized files (the mp4's are roughly 5GB in size).
Being a newbie, I'm fearful of making edits, as I want each original mp4 version to remain as my master so to speak; so, I'm thinking I should create a duplicate of the mp4 video and save that to my iMac for editing. Then, when the edits are complete, I guess I'd save/name it as, say, YouTube Video #1, and it would then be stored alongside the .mp4 masters on the Seagate external drive. Yes?
My main goal is to upload the edited mp4 videos to my YouTube channel, and invite others to view. I have no special editing software at this point. Just iMovie. I've never edited videos before, but as a former photographer I have edited thousands of still images in Photos. Looking for a simple video editing process. Please help!
iMac 24″