Some ideal statements to add in the description of your video, in case you are using someone else's content in it can be:
“All the videos, songs, images, and graphics used in the video belong to their respective owners and I or this channel does not claim any right over them.
Copyright Disclaimer under section 107 of the Copyright Act of 1976, allowance is made for “fair use” for purposes such as criticism, comment, news reporting, teaching, scholarship, education and research. Fair use is a use permitted by copyright statute that might otherwise be infringing.”
If you have copyright issued for your own content in the video then you can simply write:
“. Any reproduction or illegal distribution of the content in any form will result in immediate action against the person concerned.”
Hope this helps,
Cheers!