(0,-6) will help you attain d (i.e. find f(0) ). It's a good attempt at 3.1, but you need to substitute points A, B, and C into f(x). Since you can obtain d, then you only have a,b, and c left. This means that you need 3 equations (hint: substitute A and C to get two). In order to get a 3rd equation, note that A is a critical point (read: do something with the derivative). This will get you a 3rd equation, and then use these three to find a,b, and c.
3.2 is asking about the critical point B. Note that you find these with the first derivative.
I only see up to 3.6 with the image link you provided.