What do I Know About Setting?
So you never fought in the war between orcs and humans. That doesn't mean that you can't incorporate your personal experience into that wonderful made up world you've created. Memories of the small town in which you grew up or the apartment in which you currently dwell can provide all you need to create a palpable setting that your reader can touch, smell, see and touch. Have you ever lived in an apartment that was sweltering during the summer months? Remember how you felt? Frustrated? Helpless against the merciless dry heat that was forcing your skin to regurgitate its moisture in futility? Use those feelings and thoughts to describe the heat your character feels as he crosses the Mojave desert in search of buried treasure. The lonely midnight walk to your car in that shady parking lot can lend invaluable pieces as you construct a dank cave in which your characters become lost. Dark is dark, whether you are creeping through the echoing concrete halls of a parking structure, or barely surviving in the belly of a man eating whale. The feelings are the same; lonely, helpless, vulnerable. Search your memories for the feelings you want to communicate and use them to your advantage.
Trust that What you Know isn't Stupid
Look at the lives of some of the bigtime authors before they made it big. Stephen King was relatively poor and teaching creative writing in college when Carrie made him a wealthy man. J.K. Rowling was hanging out in coffee shops, struggling to make ends meat when Harry Potter was born. However, they were able to create wonderful characters with real, believable relationships in otherworldly settings. You have the experiences necessary to write compelling settings. Trust yourself and what you know. You have experienced enough to write fiction, even if an autobiography is out of the question. We can't all be Lady Gaga...