My cousin said he wants to be my friend....what do people mean by this?

It seems like he does understand, and it's perfectly understandable that you would be needy when your parents divorce at such a young age. Try to respect other's boundaries though and don't be too clingy. If he says that he wants to be your friend that means that he's reaching out to you and trying to bring you two closer. Do what feels right to you, you are the most important person to take care of for yourself.