There are three kinds of galaxies: elliptical, irregular, and spiral. Elliptical galaxies have most of their stars in a sort of lemon-shaped (elliptical) area. You could make a model of an elliptical galaxy by making a ball of Play-Doh, then rolling it just a little flat in one direction. Irregular galaxies are just a bunch of stars grouped together in no particular shape. You could make a model of an irregular galaxy by dropping a handful of dry rice grains in the center of a plate, then dropping another handful across the whole plate. (And then you'd want to imagine the whole thing in three dimensions instead of flat.)
The third kind of galaxy is the kind we live in--a spiral galaxy. The Milky Way has hundreds of billions of stars scattered around in three main parts: the nucleus, the spiral arms, and the disk. Learn lots more about what kinds of stars are in each of these parts here.