what are the experiences of story?

This all depends on what you mean by experiences. Each character "experiences" different things. Most of the characters experience hardship just trying to survive. They also, however, experience a sense of hope and optimism no matter how bad things get.

Mean that talk about good deed and bed deed of characters

These types of experiences are scattered throughout the novel. Really, just take a look at a short summary online if you don't have the book. Everything from father's alcoholism to the kindness of the DesSilva's and Mr. Panwallah can be considered.