Answer:
1. I assume you just pick some arbitrary x and y numbers to plug in the equation. but if you answer part b and c first, part a might be easier for what values to choose.
2. if you do a quick browser search for how to find the max height of a parabola, then you can learn how to.
3. research on Browser. you can also just make y = 0.
vertex is max height, both zeros is just solving the equation for the x values. axis of symmetry is just the vertex point with a line through it.