How to Creatat a plugin to include custom code in the functions.php file and CSS directly in your theme

past this code on .php text file and pute on folder and make comprace

demo download

<?php
/*
Plugin Name: Editor
Description: Change the login URL for wp-admin.
Version: 1.0
Author: Bishal Thapa
*/

  // Customize CSS Code Here down ............................................................................................................
  
function custom_woocommerce_css() {
    ?>
    <style>
        
/* Hide the menu item for logged-out users */
body:not(.logged-in)
.hide-for-logged-out {
display: none !important;

}
    
    // Customize CSS Code Up Side ............................................................................................................
    </style>
    <?php
}

add_action('wp_head', 'custom_woocommerce_css');












// Function.php Code  down Here ............................................................................................................


// Redirect 404 Page into Home Page
// Redirect 404 Page into Home Page
function redirect_404_to_homepage() {
    if (is_404()) {
        wp_redirect(home_url('/shop'), 301);
        exit();
    }
}
add_action('template_redirect', 'redirect_404_to_homepage');