Hi Sandra,
I am sorry for your loss. You are kind to take in the parrot and try to make things work out. He may still need more time to settle in. He has been through a lot and doesn’t understand the changes in his life. Greys are notorious for resisting change. You might do some research and find a good avian behaviorist, since you have never owned a bird. A grey can be a challenge to an experienced bird owner, so you could have your hands full depending on this bird’s personality. Mainly you will need to take things slowly and not force anything. I can provide some links on working with a new bird. There are also some African Grey groups where other owners help each other. Whatever you choose, I think a behaviorist or other owners or both will be the way to go rather than only reading. Good luck with this guy! I am sure ya’ll will be good friends.
Caring For Your Bird
Bird Food Guide
https://lafeber.com/pet-birds/category/behavior/
Thank you for asking Lafeber,
Brenda