Q: I want make a apple id for my 12 year old where is the page for that

Once you have updated to iOS 8, under iCloud you will find a new setting called Family Sharing.  After you have set yourself up as the organizer, you can then create the child Apple ID using the same section.  Note:  You may be required to provide a credit card (Not debit card) if the child is under 13.

HTH

Family Sharing and Apple IDs for kids

You might want to consider this

Create an iTunes Store, App Store, or iBooks Store account without a credit card or other payment method

and more importantly  this

What is Apple ID for Students?