If faced with such a wide open question you could do some research and start asking all the questions you think of, but you're then just hoping to narrow in on something by luck. The "Strong Opinions, Weakly Held" method works well here, if within the first week you can learn enough to form some opinions, you now have some ideas to test against and disprove. You can start to decide on what information is important and what isn't important, rather than trying to gather all the possible information and synthesize it later on.
If you have an opinion such as "you should formulate a strategy to sell direct to the consumer instead of relying on distribution alone" you have a starting point and have narrowed things down from "how do we sell more things?". You might not have one opinion, you might have five. It takes experience to come up with opinions quickly when faced with limited data and potentially a large problem space.
It's hypothesis-driven decision making. It does require both iteration and the willingness to let your original opinions go--kill your darlings.