functions.php

function twentyseventeen_widgets_init() {
 
    register_sidebar( array(
        'name' => __( 'Main Sidebar', 'twentyseventeen' ),
        'id' => 'sidebar-1',
        'description' => __( 'The main sidebar appears on the right on each page except the front page template', 'twentyseventeen' ),
        'before_widget' => '<aside id="%1$s" class="widget %2$s">',
        'after_widget' => '</aside>',
        'before_title' => '<h3 class="widget-title">',
        'after_title' => '</h3>',
    ) );
 
    register_sidebar( array(
        'name' =>__( 'Front page sidebar', 'twentyseventeen'),
        'id' => 'sidebar-2',
        'description' => __( 'Appears on the static front page template', 'twentyseventeen' ),
        'before_widget' => '<aside id="%1$s" class="widget %2$s">',
        'after_widget' => '</aside>',
        'before_title' => '<h3 class="widget-title">',
        'after_title' => '</h3>',
    ) );
    }
 
add_action( 'widgets_init', 'twentyseventeen_widgets_init' );