It can definitely be a bit complex to get installed/set up. Maybe if I have time sometime I'll try and write up a good guide on how to set it up (if there isn't already a better one out there already).

Once it's set up though, it's pretty simple.

Open a powershell (on windows), or terminal (on linux/mac) and type the below command

youtube-dl "enter url of channel, playlist, or video here"

It'll then download the above video/channel/playlist to whichever folder path is open in the powershell/terminal.

I sometimes add a "-i" command switch in there for ignoring failed downloads when downloading a large channel. That way if you're downloading say 2000 videos, and there's a connection failure on the 700th one, it'll skip it and continue rather than erroring out causing the need to restart from the beginning. If you don't do this and it does fail and you restart it, it won't redownload everything again as long as the files are in the same folder (from before the download failure), it'll just check each one in the list to make sure it's downloaded (which can still take some time for thousands of videos).

youtube-dl -i "channel url here"