I am planning to visit my son with family. Do they have to be present when I apply for the visa

I am planning to go with my wife and my step daughter to Shanghai to visit my step son. I need to know if we can fill for group type or must be individuals. I have letters of invitation copy of the airline tickets and passports (US). I will down load and fill the visa application and print it. I understand I have to pay the fees. Do I need any other document?

Thank you,

Nabil L Mina