### get coordinates and function value as list

I am quite new in sage as well as in programming, so please if you explain this, please do it thouroughly.

Let's assume we have a simple function like F(x,y)=x+y.
Is it possible to create a list, something like (x,y,F)?
To make clearer a list in the form of (value_of_x_coordinate,value_of_y_coordinate,value_of_function) for instance (1,1,2) or (1,2,3).
If this is possible, how can we transform the coordinates x,y by operating somehow on the list e.g adding on both x and y, a number N.