Q: Parent Account with no apple device

Hello

Just bought my son iPhone 5s and it's coming tomorrow. I want to set him up a child account on the back of my apple id.

I have an apple id and gave red how to set it up but here are my two issues:

To set up a child account I need to use an ape device at ios 8 IR higher.... I will not have one until tomorrow so I guess I set the phone up with my ID then create the child account then log off and log back on with child id?

Second issue is I want him to use ask to buy but myself and wife use android devices. How do I authorise his purchases if I have no apple device?

Would appreciate any advice. :-)