Gentle displine for 2yo

Hello sisters,
My 2 year old son has recently developed some pretty awful behaviors and I was looking for some gentle ways of dealing with these.
He will point and tell someone off (in baby language, in an agressive, loud tone) I don't do the whole point thing so I don't know where he gets it from. He will also hit people while telling them off or raise his hand at them, I have also neve done this so don't know where he has picked it up from.
He can also target someone and just be nasty, lately it has been my partners cousin who we are very close to. He will yell at her every time she speaks (even if it wasn't to him) or looks at him. If we are all in a room he will push her out of the room and close the door behind her. She is very soft. gentle and loves him very much. I don't see anything she could have done for him to be like this. He can also get nasty with myself sometimes and favors his father, I know it is normal for him to favor one of us, I just want him to stop being so nasty.
Thankyou..