Aparabola has a minimum value of 0, a y-intercept of 4, and an axis of symmetry at x = -2

Since the minimum value is 0 and axis of symmetry is -2 this means that the vertex is at -2,0 now with the y intercept of 4. You can now plug the values into Vertex form which will be y=a(x-h)^2+k. a being the shrink or stretch of the parabola, h being the x value of the vertex, and k being the y value of the vertex. with all of that plugged in it should look like y=(x+2)^2. You can check this equation by plugging in 0 as x which should find the y intercept of 4. So it should then look like y=(0+2)^2 -> y=(2)^2 -> y=4