function aixcey_theme_enqueue_styles() {

    wp_enqueue_style(
        'main-style',
        get_stylesheet_uri()
    );

}

add_action('wp_enqueue_scripts', 'aixcey_theme_enqueue_styles');

function mycustomtheme_setup() {

    add_theme_support('title-tag');

    register_nav_menus(array(
        'primary' => 'Primary Menu'
    ));

}

add_action('after_setup_theme', 'mycustomtheme_setup');