How To Open MP4 in Windows Movie Maker - Windows 10
The best solution is often the simplest.
For those who can't find Movie Maker, I'll point you to this video: • Where is Windows Movie Maker in Windows 10
I haven't tried that DaVinci program yet, and I do so little video editing that I probably never will.
Just remember that the best way to learn is to ask questions. Sometimes asking a search engine is enough. Personally, I despise Google and prefer Bing (more reliable results, as I've noticed), but use whatever works best for you. I know it's a pain to troubleshoot, especially if you're like me where your entire tech expertise comes from learning about problems as they arise, rather than a formal education in computer systems. Just stay calm, and remember, nothing tech related will just take a minute (as anyone trying to setup a wireless printer knows).
A little trivia: My desktop BG is from the beginning of Assassin's Creed IV: Black Flag. :)