Tips on Customizing Tarot Card Oracle

How to Hide Card Oracle Admin Menus

function plt_hide_card_oracle_menus() {
	//Hide "Card Oracle".
	remove_menu_page('card-oracle-admin-menu');
	//Hide "Card Oracle → Dashboard".
	remove_submenu_page('card-oracle-admin-menu', 'card-oracle-admin-menu');
	//Hide "Card Oracle → Readings".
	remove_submenu_page('card-oracle-admin-menu', 'edit.php?post_type=co_readings');
	//Hide "Card Oracle → Positions".
	remove_submenu_page('card-oracle-admin-menu', 'edit.php?post_type=co_positions');
	//Hide "Card Oracle → Cards".
	remove_submenu_page('card-oracle-admin-menu', 'edit.php?post_type=co_cards');
	//Hide "Card Oracle → Descriptions".
	remove_submenu_page('card-oracle-admin-menu', 'edit.php?post_type=co_descriptions');
	//Hide "Card Oracle → Demo Data".
	remove_submenu_page('card-oracle-admin-menu', 'card-oracle-admin-demodata');
	//Hide "Card Oracle → Affiliation".
	remove_submenu_page('card-oracle-admin-menu', 'card-oracle-admin-menu-affiliation');
	//Hide "Card Oracle → Contact Us".
	remove_submenu_page('card-oracle-admin-menu', 'card-oracle-admin-menu-contact');
	//Hide "Card Oracle → Support Forum".
	remove_submenu_page('card-oracle-admin-menu', 'card-oracle-admin-menu-wp-support-forum');
	//Hide "Card Oracle → Upgrade".
	remove_submenu_page('card-oracle-admin-menu', 'card-oracle-admin-menu-pricing');
}

add_action('admin_menu', 'plt_hide_card_oracle_menus', 1000000000);

Where do I put this code?

How to Hide Card Oracle Meta Boxes

function plt_hide_card_oracle_metaboxes() {
	$screen = get_current_screen();
	if ( !$screen ) {
		return;
	}

	//Hide the "Previous Page" meta box.
	remove_meta_box('back-metabox', $screen->id, 'side');
	//Hide the "Front of Card Image" meta box.
	remove_meta_box('postimagediv', $screen->id, 'side');
	//Hide the "Settings" meta box.
	remove_meta_box('card-reading', $screen->id, 'normal');
	//Hide the "Reverse Card Description" meta box.
	remove_meta_box('reverse', $screen->id, 'normal');
	//Hide the "Settings" meta box.
	remove_meta_box('card', $screen->id, 'normal');
}

add_action('add_meta_boxes', 'plt_hide_card_oracle_metaboxes', 20);