You can not do what you are suggesting purely client-side (well not for a realistic number of films).
- You need to build a server-side database of film titles, image names etc... and their classifications.
- You then need to write a query which will return the info on the films that are in the respective category.
Note: I'd suggest that, as the categories are not necessarily exclusive, you need a field for each category, with Y/N flags in each for each film. E.g. For a comedy action film you would have "Y" in the comedy and action fields and "N" in the rest. If this is gobble-de-gook to you, then you need to learn the basics of building and using databases before you attempt to build such a site.
Oh, and by the way, I'm assuming you have no intention of putting the site live? All the films you include are copyright, and your site would be liable to be closed down by the copyright holders. Also we do not condone piracy, and have no intention of aiding anyone infringing copyright.