Publishers have Writer Phobia
So you want to write a book? Nothing to it – and usually nothing for it. But that's another matter.
First, you need to choose a genre and then you need a plot and believable characters. You have to think about those characters in such detail that you know more about them than you do about your mother. Some writers say the characters tell them where the plot should go next. Sometimes I worry about those writers.
About characters: do NOT, under any circumstances whatsoever, include someone you know, as a character in your book. Don't even give the stunningly beautiful heroine or the stunningly handsome hero who is tall, incredibly handsome and has wide shoulder and narrow hips, the name of someone you know.
Of course, if you don't care that no one you know ever speaks to you again, including the person you used and the jealous person whom you didn't use, go ahead and get sued. It is raw material for your next book.