What are the raw materials?
Starch is a polysaccharide, therefore its raw materials are monomers. In this case, the monomer required to create starch is glucose.
Where is it created?
Light turns into chemical energy by chlorophyll or chloroplasts (organelles) which forms a chemical reaction that is stored as glucose, the glucose then turns into starch. Glucose can only be created through photosynthesis, and photosynthesis requires light. Plants create starch so that it can be broken down into glucose to be used as energy when there is no light.