The vertex is where the parabola changes directions, or in simpler terms, at the parabolas lowest point. Unless the parabola is upside down, then the vertex is where the highest point is.
The acid of symmetry is the line where the parabola can be divided evenly. This is almost always where the vertex is, except it continues on.
The y-intercept is where the parabola intersects with the y-axis.
I’ve answered the question below in the picture (my graph is not to scale but the answers are correct for yours)
Hope this helped and good luck!!