What are you actually seeking to do?
If you only want to download Youtube files, there are plenty of free online services that can do it for you. However they all have their limitations. For the best (genuinely) free software, see here:
https://www.techradar.com/uk/best/free-youtube-downloader
VLC (which I hope you've already got on your PC) can also stream and save Youtube videos. (It's particularly useful if, say, you want to save just a three-minute song from a two-hour video. You can just download the section you need).
If you want to convert video files between different formats, Any Video Converter Free (mentioned in my link above) will do the job for you.
If you want to edit videos, Shotcut isn't too difficult to work with
https://shotcut.org/
The same goes for OpenShot
https://www.openshot.org/
VideoPad's free version is also fairly intuitive. (It has certain limitations when compared to the full version but it's good enough for most purposes. I use it myself):
https://www.nchsoftware.com/videopad/index.html
(Look for the small 'Get it free' link on that page).
Lightworks is fantastic. (It's been used to make many Hollywood movies). The free version does everything that the full version can except for exporting at the very highest resolutions. However it's got a very steep learning curve:
https://www.lwks.com/