Those dings should fill easily enough with a little gel coat repair kit like this . http://www.wholesalemarine.com/p/F-E...FQsGnQodtHkABA
Going to take some experimenting to get the color to match.
The crack are another story. Filling them isn't going to be possible. A light coat of anything on top is just going to crack again in short order. That is a job for a pro.