My typed message somehow got lost as it did not get posted, so I summarise what I wrote.

(If you can see this message, means it is not lost, but the previous long text did)

You can do these

- find the x-intercepts by letting y = 0 (effectively solving a cubic equation; check the values using your calculator feature just in case the solutions, if any, are irrational)

- find the turning point(s) of the curve (I am expecting two turning points based on the second part

Note that for a positive cubic graph, the graph will start very negative and end off very positive.