My son was a happy vibrant little boy, but when autism came much of that changed, at least it changed externally. My son used to look at my face, smile, laugh, sing songs, and loved to play games. All of that changed.
The first thing I did was hold my son and tell him how much I love him. He did not hug me back nor did he look at my face.
I st...arted playing a game with him, one of his favorites, peek-a-boo. In this version of the game I used my hands as blinders holding them over his eyes (not touching eyes) and then opening them like shutters. Each time I opened my hands to reveal his eyes, I would make some sort of funny face. At first he would not look, but after a few months he began responding to our little game. It appeared that he was anticipating something. I don't know if he equated it to being a fun or funny something, but he did actively look at my face.
I did not need my son to look in my eyes, I know that can be very difficult, but I did want him to see my face and feel safe looking at it.
This simple game was our first real connection after autism struck. That was many years ago. My son is 14. Even now he still makes a point to looks at my face everyday, even if just for a moment and he smiles.
Find ways to connect with you child. Make up games or sing songs do what ever you can. Once that connection begins, they sky is the limit.
It doesn't get much better than that.