There aren't any hard-and-fast rules about writing a book because it's not something with a definite right or wrong (unlike math). My advice from personal experience would be to first silence your inner critic and keep writing. My policy is that you must have quantity before you begin to work on quality. If you're comfortable, show your story to a friend, preferably someone who is good at English or also an aspiring writer. They would serve as a second pair of eyes and second opinion to help finetune your story. In the end, though, it really boils down to practice. Keep writing, read some books, and in a few years you will definitely improve.
Good luck. I started writing 'seriously' at 10 and 6 years on I'm still not confident on publishing, so that should give you some idea for how long it'll take.

Source(s):

Personal experience

The Earth's Children Series, starting with Clan of the Cave Bear. It's an epic chronicaling the life of a young Cro Magonon woman, who does have special powers. (Romance doesn't hit until half way through the second book, "The Valley of the Horses," but Jean Auel has won best exotica author for a few years with the books after that. And, no, you don't have to read the first in the series. One complaint about her is she over does on summing up previous books in each of her books.)

What is the moral out of the book "The Catcher in the rye" ?

What are the key takeaways, the moral and the things we should know ? Thank you in advance for your answers !