There is a very great website called Desmos that can efficiently graph any equation. I think it will help a lot :)
Since this function is an absolute value, then it would look like a V shape on a graph. The vertex will always start at (0,0). Inside the absolute value x is subtracted by 3 which means the vertex will move to the right by 3 units. The entire function is added by 6 which means the vertex will move up by 6 units. I've attached a graph showing the final vertex of f(x)=-|x-3|+6 which is (3,6)
Hope This Helps :)