Custom post type with new Roots

I am trying to create CPT , I added this to custom.php but can view the post. It just show 404 page.

/**Add New Custom Post Type**/
function my_custom_post_product() {
  $labels = array(
    'name'               => _x( 'Projects', 'post type general name' ),
    'singular_name'      => _x( 'Projects', 'post type singular name' ),
    'add_new'            => _x( 'Add New', 'book' ),
    'add_new_item'       => __( 'Add New Project' ),
    'edit_item'          => __( 'Edit Project' ),
    'new_item'           => __( 'New Project' ),
    'all_items'          => __( 'All Project' ),
    'view_item'          => __( 'View Project' ),
    'search_items'       => __( 'Search Project' ),
    'not_found'          => __( 'No products found' ),
    'not_found_in_trash' => __( 'No products found in the Trash' ), 
    'parent_item_colon'  => '',
    'menu_name'          => 'Projects'
  $args = array(
    'labels'        => $labels,
    'description'   => 'Holds your Project data',
    'public'        => true,
    'menu_position' => 5,
    'supports'      => array( 'title', 'editor', 'thumbnail', 'excerpt', 'comments' ),
    'has_archive'   => true,
  register_post_type( 'product', $args ); 
add_action( 'init', 'my_custom_post_product' );

using this steps, but now using base.php and page.php. I want to use base-pippo.php ??

I created a file single-pippo.php with get_template_part(‘templates/content’, ‘pippo’); inside;

I created a file inside templates directory named content-pippo.php with the code for content (h1 and the_content());

I created a base-pippo.php equal to base.php excluding the sidebar.

Why are you not using functions.php?

and what to add in function.php ? doesnt matter if function.php or custom.php

how can I create new base-post.php just for posts or any custom post types ???

The Roots documentation and several other threads have answered this question in depth. Please re-read the wrapper documentation and use the search function.