Since the person wanting to learn how to make videos has a Windows 10 computer, I would recommend that you start there, with the software that they already have. Click on the Windows start menu and type "video editor" without the quotes. That is exactly the first thing I did the first time I wanted to try to edit a video file. I checked to see if Windows had a tool that ships with the operating system.
To my surprise, there was a built in app named "video editor" and it was intuitive
enough that I managed to take a friend's collection of trail camera videos and combine them into a single file to upload on YouTube. I reposted the sample video just now for this
thread
Since that one time in October of 2021 I haven't had a need to edit any more video files, but now see that Microsoft has produced their next video editor called "clipchamp". Both of Microsoft's video editors are documented here:
Microsoft Windows 10 video editing apps
Here is the documentation on
How to Create a YouTube channel which I will admit I have not read. I did try reading the documentation a year ago and found it confusing. YouTube is not the only game in town for posting videos, but it is the most well-known. Since I have almost zero experience posting videos, I'll let others more qualified address that subject. I will comment that even though I've been a software developer and computer infrastructure engineer, I find the whole YouTube channel creation and management user experience sufficiently confusing to keep me from wanting to learn more about it. So if you find the YouTube authoring experience confusing, that isn't on you. It is a somewhat complicated process and I think they haven't done a very good job of making it easy to understand.