_PABLO on "how to add a menu page with elements wordpress?"

Hello, I have this example plugin for creating a page in the admin panel:

add_action( 'admin_menu', 'register_my_custom_menu_page' );

function register_my_custom_menu_page(){
	add_menu_page( 'custom menu title', 'custom menu', 'manage_options', 'custompage', 'my_custom_menu_page', plugins_url( 'myplugin/images/icon.png' ), 6 );
}

function my_custom_menu_page(){
	echo "Admin Page Test";
}

All working, but I don't know how place elements of wordpress.
I would like to have on the new page function: edit header, edit title and description website. For all the answers, thank you.