@cheetah is a bot that looks for copy/paste work from another site. In this case, much of the text from your post here looks like it came from the 'Overview' tab on the link it posted. It's not accusing you of plagiarism, just pointing out the similarities. It's always best to write your own content, but if you want to do a cut/paste from somewhere else, make sure you source it so other people know the writing wasn't yours. :)

Cheetah only checks for copied text, not videos, so that's what it's calling you on. Your YouTube content is your own.