If you're working on a science fair project, browse through the Science Fair Spotlight and The Science. If you don't find help there, the expert still may be able to help. Make sure you tell the expert what branch of science you are studying and some details about yourself and, perhaps, what significant adults in your life do for a living. Maybe you could do a biology experiment on how waste oil affects the germination of plants. Maybe you could experiment on whether scents in the air affect buying patterns or discover what colors make the best sale sign.
Good science is inspired by curiosity.
My sister, an equestrian, experimented with how fast compost rots and what can be done to accelerate it. Even in something like stamp collecting, one can think of good experiments. Once you have a question the expert can help you find information in order to find an answer.