How do I get royalty free music, images ,video clips, cartoon characters with different actions and emotions for short filmmaking
By buying it or looking for freely licensed media (such as creative commons).  I'm not sure what more you are looking for.  Royalty free content still has to be purchased, there are online stores that specialize in it.  The only trick with it is that you don't have to pay for each copy you make of the final media that you use it in.  There may also be other limitations (such as how much of the media it can make up).  Be sure to read the license for the media closely prior to purchasing to make sure it meets your needs.