Au pair (Some questions!!)

Hello! Does anybody could help me with the answers to the next points:
I have some questions the au pair visa. There are some conditions required to be an au pair:

1.he/she does not have a duty of care or is responsible for the actual care of
his/her own family members (for instance, children or parents).
What is the form of the document proving that?
2.he/she does not constitute a risk to the public order.
The same question.What document must I provide?
3.the declaration of background.
What document must I provide? Does a special form exist or it's a letter written by hand and signed?
What of theese documents be legalized in the Ministry of Justice?

4.he/she has not previously stayed in the Netherlands on a residence permit
I have never been to Netherlands before. How should I prove it?
5.he/she did not previously work for your family abroad. The same question.

6.he/she must sign a declaration of awareness.
Does a special form exist or it's a letter written by hand and signed?

Hoping to hear from you soon!
Best regards. Elena. :unsure: