At a guess, your quote is in the wrong place:
$new = file_get_contents ('https://...1b40f' &language=es-MX&page=1);
^
Either you need a comma between the two parameters, or more likely the quote should be at the end of the complete string:
$new = file_get_contents ('https://api.themoviedb.org/3/movie/550?api_key=3b5be2c605681b40f&language=es-MX&page=1');