How to find the y of the vertex. How can I find the y? The...

From the roots ($x$ intercepts), you can write the equation of the parabola as: $y=a(x+1)(x-5)$
When $x=0$ (this is the $y$ intercept), $a(-5)=5$, so $a=-1$.
So $y=-(x+1)(x-5)$
Set $x=2$ for the vertex (turning point) to find $y=9$.
(From what you wrote, I assume you know how to find the $x$ coordinate of the vertex or turning point, but just for completeness, it is the arithmetic mean (average) of the two real roots, so here it is simply $\frac{-1+5}{2}=2$).

Since$x=-1$ and $x=5$ are zeros of your parabola, your parabola is
$y=a(x+1)(x-5)$
Since your $y$-intercept is $(0,5)$ you get
$5=a(1)(-5)$
which implies
$a=-1$
Thus your equation is
$y=-(x+1)(x-5)$
You may write it in standard form
$y=-x^2+4x+5$