If your using any of the newer versions of maya (i think 7.5 and up), they use Mesh and Edit Mesh drop down menus which replace the Polygon menus. the Create Polygon Tool is under the Mesh dropdown. if you cant find the Mesh dropdown make sure your in the Polygons subset (over at the left theres another dropdown underneath the file and edit bar, you can select Animation, Polygons, Surfaces, etc; switch this to polygons.)