what is the purpose of the other wolfs like sam in the movie why is it just about the main characters

here are not only 1 vapire so why should there be i wolf

Um well because their in the book and play an important role. And their important in the rest of the saga. Why would Ты want them left out? The story wouldn't be the same and then it wouldn't be the same wonderful story from the Книги that we all love.