Reestablish Apple ID!!!!!!!!!! Can you help us?

Hello. I need help for my son’s account. He don’t remember his Apple ID and e-mail. We know only the password from Apple ID(( So he can’t use his new phone correctly. And he upset about his purchases and VIP status in games. Because he can’t reestablish his account on new phone. The previous one was broken at all. And we can’t fix it. We try different ways to remember Apple ID, and try to reestablish it with website Apple. We don’t use our email anywhere, only to make Apple ID. We are trying to get Apple for about 10 days. And hope for your help so much. Thank you