You are graphing the function

y = x + 3

The graph is a line. Select a rectangle to zoom in and read the points of the line.

You can also find the points of the line of you plug:

For x = 0 we have y = 0 + 3, that is y = 3, thus (0, 3) is a point of the graph.

For x = -3 we have y = - 3 + 3, that is y = 0, thus (-3, 0) is another point of the graph.