Everybody has a story to tell, but is it worth telling? Can your real life story grab the reader's attention from beginning to end? Be compelling, exciting, adventurous, thrilling, mysterious enough for your reader, or is it just a great true story but not necessarily novel material? Turning a true story into a fictional masterpiece is much more difficult than you might think, especially for a first time writer, yet it is not impossible. For the most part many great fictional works are drawn from real life experiences, places, people, and events- it is making those elements of your story become larger than life that will turn them into something readable, as well as interesting to your audience.
Even if you think your true story has all the characteristics of a great piece of fiction that might not be the case- lives and events in ordinary people's lives, on the whole, are more mundane than you think and typically wouldn't interest the average reader has much as you might like to believe- even if you do have a good true story of your own to tell. When creating fiction you will need to make the characters, events, settings, experiences, of your true story more exciting, interesting, disturbing, emotional, and so on to make them worthy of being read. This comes with not only having a talent for writing, but the skills and insight to pen your words in a manner which will appeal to a broad audience of readers- especially if you want it to be successful.
In making your true story into a work of fiction it will also be important to remember not to use real names of people involved in and with your story. Characters in your personal story, even though they are real people, should be unrecognizable to your readers. They key to any great novel will be making it believable. A great resource to understand how to turn your true story into fiction would be to watch a movie that has been based on a book that is a true story. Reading the book first and then watching the movie will give you a better insight as to how it is done. There a number of local writer's workshops out there also that you can attend -learning how other writers have turned their stories into fiction can be invaluable when it comes to writing your own.
Certainly, turning a true story into fiction will be a challenge for any new writer, but it's not impossible- if you think you have a really great story to tell, tell it!- because no one can predict when the next bestseller will come along, and who knows, it might just come from you!