my kid is 15 years old. got EAD card(485pending).

He is going to apply social security number for him. what document should he take?

1. passport with I-94
2. birth certificate
3. EAD card
4. H4 approval notice
5. 485 receipt
6. AP approval notice
...

anything else? or what are not necessary for the above?
But per instruction, people must provide at least two separate documents. what does it mean?