I think you need to figure out why he thinks he’s ready to start dating, and evaluate if he is.
there are some guys who are ready to be married at 21, and he can always come back to American and learn here.
but talk to him, ask him why he thinks its time for him to start dating
also, if he has a sister around the same age (or theoretically he could do this with a parent), make him have a conversation THAT DOES NOT CENTER AROUND HIS LEARNING. because that is hwat he will need to do when he starts dating, and he needs to know how. if his mind is still too in the clouds to do this, then he’s not ready.
I did this for a brother of mine, and as much as it wasn’t really fun for me, it took just 20 minutes and it let my parents see that he was ready to enter that real world.