Apple account for autistic son

All users should always have their own unique AppleID. You’ve already covered this essential step.

You’ll likely wish to set-up ScreenTime on your Son’s iPad - regardless of the level of controls or restrictions that you subsequently apply. Ensure that you create a ScreenTime Passcode - known only to you - and differs from the iPad Passcode that is used to lock the iPad. When setting-up the ScreenTime Passcode, you’ll be prompted for AppleID credentials that will be used to reset the Passcode if it is forgotten.

Use Screen Time on your iPhone, iPad, or iPod touch - Apple Support

Having enabled ScreenTime with a Passcode, you can consider the controls and restrictions (if any) that you wish to apply. Also consider Family Sharing - where you can selectively share purchased Apps, subscriptions and Apple services.

Family Sharing - Apple

Set up Family Sharing – Apple Support

Share App Store, iTunes Store and Apple Books purchases with Family Sharing – Apple Support

How to create a new Apple ID – Apple Support

https://www.imore.com/how-set-up-family-sharing-iphone-ipad

You are very welcome.

When enabling ScreenTime, you’ll be asked if you are setting it up for yourself or a child. This question is poorly worded - as the “child” response applies to any device that is being managed by a family organiser. The “child” may be young, adult or elderly - all of which have circumstances that require the device to be effectively controlled by a “parent”.