As of September 1, 2021, you only have access to a limited version of YouTube designed for schools, automatically applied to students under 18. This change only impacts your YouTube experience on your school account. It does not change what you can see and do on YouTube while signed in to your account.
Saving Youtube Content
Use Google Takeout to download and save your videos and other data (like comments and search history) that you’ve created on YouTube. You will have until June 2022 to download your data via Google Takeout.
References
https://support.google.com/youtube/answer/10977326?hl=en