Well, the classic place to start a story or novel is one of three places: the State of Perfection, the change of the State of Perfection to the State of Imperfection or the State of Imperfection itself.
For example, in The Godfather (1972), the story starts at a State of Perfection - the Corleone family is whole.
For example, In 12 Angry Men (1957), the story starts at a State of Imperfection - a murder has been committed and an accused is on trial.
You can look at the State of Imperfection from a number of viewpoints. For example, the dominant Antagonist in an Ordinary World and the subdued, repressed Hero in an Ordinary World. Your story will reverse that situation. In The Lion, the Witch and the Wardrobe (2005), Narnia starts off with the dominant white witch ruling Narnia and repressed, subdued children. The story reverses that situation.
Problems are external and internal. Commonly, some external goal will drive the story, for example, Indy's looking for an ark in Raiders of the Lost Ark (1981). But an internal goal will underlie the upper goal, for example, Indy's got to get over his losing streak to Belloq. Goals are layered.
Once the problems have been identified, you need to move your heroes, characters, and archetypes out of the Ordinary World and into the New World, where change occurs. This is explained in detail in the 2000+ stage Hero's Journey and Transformation through a New World/State at http://www.clickok.co.uk/index4.html