<?php


function example_customizer( $wp_customize ) {
    
    
/* ============== HEADER LOGO
========================== */
    $wp_customize->add_section( 'logo_section' , array(
    'title'       => __( 'Logo' ),
    'priority'    => 30,
    'description' => 'Upload a logo in the header',
        ) );
        
    $wp_customize->add_setting( 'logo' );
    
    $wp_customize->add_control( new WP_Customize_Image_Control( $wp_customize, 'logo', array(
    'label'    => __( 'Logo' ),
    'section'  => 'logo_section',
    'settings' => 'logo',
) ) );


/* ============== Pages
========================== */
    $wp_customize->add_section( 'pages_section' , array(
    'title'       => __( 'First Page' ),
    'priority'    => 30,
    'description' => 'Select the first page:',
        ) );
        
    $wp_customize->add_setting( 'first_page' );
    
$wp_customize->add_control(
    new WP_Customize_Control(
        $wp_customize,
        'your_setting_id',
        array(
            'label'          => __( 'First Page?', 'theme_name' ),
            'section'        => 'pages_section',
            'settings'       => 'first_page',
            'type'           => 'dropdown-pages'            
        )
    )
);


}
add_action( 'customize_register', 'example_customizer' );