If the vertex of a parabola is the point $(- 3, 0)$and the directrix is the line $x+ 5 = 0,$ then its equation is

Axis is along x-axis and distance  from vertex to directrix $x+5=0\text{ is }\frac{\left|-3+5\right|}{1}=2=A$

$Equation of parabola is Y^2=4AX\Rightarrow (y-0{)}^2=8(x+3)$