I found this image by searching "kitten" on Creative Commons' website. This image is sourced from Flickr by the author Mathias Erhart, and I did not alter the image in any way. It is licensed under the Attribution-ShareAlike 2.0 Generic License (CC BY-SA 2.0), this license states the following:
Share: Copy & redistribute the material in any medium or format
Adapt: Remix, transform, & build upon the material for any purpose even commercially.
Attribution: You must give appropriate credit, provide a link to the license, and indicate if any changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
ShareALike:If you remix, transform, or build upon the material, you must distribute your contributions under the same license as the original.
I also found this image through Creative Commons again and comes from Wikimedia Commons. The author is user "Nagahitoyuki". I did not make any changes to it. It's licensed under the Attribution-ShareAlike 4.0 International License (CC BY-SA 4.0) , this license states the following:
Share: Copy & redistribute the material in any medium or format
Adapt: Remix, transform, & build upon the material for any purpose even commercially.
Attribution: You must give appropriate credit, provide a link to the license, and indicate if any changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
ShareALike:If you remix, transform, or build upon the material, you must distribute your contributions under the same license as the original.
I found this audio file through creative commons, and it led me to the site Freesound. The author is tuberatanka and the audio title is "Cat Meow." This audio is licensed under CC0 1.0 Universal (CC0 1.0) Public Domain Dedication. I did not make any alterations to this audio file. This license states the following:
No Copyright: The person who associated a work with this deed has dedicated the work to the public domain by waiving all of his or her rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law. You can copy, modify, distribute and perform the work, even for commercial purposes, all without asking permission.
Other Information:
In no way are the patent or trademark rights of any person affected by CC0, nor are the rights that other persons may have in the work or in how the work is used, such as publicity or privacy rights.
Unless expressly stated otherwise, the person who associated a work with this deed makes no warranties about the work, and disclaims liability for all uses of the work, to the fullest extent permitted by applicable law.
When using or citing the work, you should not imply endorsement by the author or the affirmer.
I found this video on YouTube, I searched "kitten educational videos" to find this clip. It is titled "How to CARE for a KITTEN - Food, Education and Health" Uploaded by user "AnimalWised" The video description doesn't have any licensing info, and I can't find anything on AnimalWised website. Based on YouTubes general licensing the following information falls under "Fair Use" because it is a general educational video intended for academic use.
In terms of sharing YouTube videos legally, it is required to credi the creator and/or copyright owner of the work.