How can I share my iPad(10th gen) with my teenage son without him having access to any of my accounts/photos/videos?

Outside of Educational and Enterprise establishments, iPad and iPhone are principally intended to be a single-user device - and are not intended to shared in the same manner as you may be accustomed when using a Windows PC or Mac computer - which has multiple user profiles/accounts.

As such, if sharing your device with anyone else, while the iPad is unlocked, they will have largely unrestricted access to everything on your iPad - including sensitive/personal information and saved credentials.

You would be best advised to entertain purchase of a separate iPad for use by your son.

Be aware that if you sign-out of iCloud and other Apple services - and allow another user to sign-in - you’ll not be able to change back for 90-days. So as to prevent account abuse, some critical Apple services will only allow one change of signed-in AppleID (on a device) in a 90-day period.

In conclusion, unless you fully understand and accept the implications, you would be well advised to reconsider any attempt to share your iPad with another user.