Disable Posts Post Type

// Remove side menu

add_action( 'admin_menu', function () {

	remove_menu_page( 'edit.php' );

} );

// Remove +New post in top Admin Menu Bar

add_action( 'admin_bar_menu', function ( $wp_admin_bar ) {

	$wp_admin_bar->remove_node( 'new-post' );

}, 999 );

// Remove Quick Draft Dashboard Widget

add_action( 'wp_dashboard_setup', function () {

	remove_meta_box( 'dashboard_quick_press', 'dashboard', 'side' );

}, 999 );