How to find the equation of a parabola and graphing it?

Find the equation of the parabola:
Before getting started with the algebra the problem provides the following information.
Focus: (-4,0)
Vertex: (0,0)

Now let's obtain the equation of the parabola.
Now plotting the points on the graph
Vertex: (0,0)
Point: (-4,-8)
Point: (-4,8)

Graph the equation of the parabola: