not actually sure what you are trying to achieve with the code. I would write something like this to get the child terms
$terms = get_terms([
'taxonomy' => array('Movies, Musics, Books, Games'),
'parent' => 0,
'hide_empty' => false,
]);
if ( ! empty( $terms ) && ! is_wp_error( $terms ) ) {
foreach ($terms as $term) {
$child_term = get_term_children( $term->term_id, $term->taxonomy )
//your code here
}
}