how to call new widgets in sidebar in custom theme?

I will put a basic code to create new widget. In WordPress its call register_sidebar; In your code, you have not put ID. Id=>your-widget-id

Put this code into your functions.php

function my_widget(){
    register_sidebar( array(
        'name' => __( 'Front Sidebar', 'yourtheme' ),
        'id' => 'sidebar-1',
        'description' => __( 'This is description', 'yourtheme' ),
        'before_widget' => '<aside>',
        'after_widget' => '</aside>',
        'before_title' => '<h3>',
        'after_title' => '</h3>',
    ) );
}
add_action( 'widgets_init', 'my_widget' );

then put this code in your index.php or sidebar.php (wherever you want)

if ( is_active_sidebar( 'sidebar-1' ) ) : //check the sidebar if used.
dynamic_sidebar( 'sidebar-1' );  // show the sidebar.
endif;

Remember to put the ID.

More http://codex.wordpress.org/Function_Reference/register_sidebar