Your question does make sense and also shows that you have a good idea of how you wish to organize your paper. Without knowing what your actual examples are, it will be a little difficult to steer you in a direction for topic categories. My best advice is to group together similar examples and try to come up with a "label" for each group. Aim for three groups, as this will make a nice 5 paragraph essay, but do not feel bound by this number.
A final note would be to consider some basic broad categories for any book/film compare-contrast essay. Some that seem generic and widely applicable are:
Similarities and differences in...
- theme or main focus
- symbolic elements or their meanings