Just give him your time and attention, they need some time every day outside the cage, talk to him and include him in on activities around the house. Put the cage in the room where the family spends most of their time when awake so he will feel a part of the "flock".
He will talk when he is ready and a few greys will not talk at all so be prepared in case you have one that decides not to speak, just love him for the unique beauty and awesome creature he is.
I would take him back in to see the vet for a yearly checkup unless he is sick in which case take him immediately.
It sounds like you need to read thru the threads here for loads of useful information that will be most helpful to you and your new grey.