To disable unnecessary wordpress dashboard items in admin section, add this below code in theme functions.php file:

add_action(‘wp_dashboard_setup’, ‘my_custom_dashboard_widgets’);

function my_custom_dashboard_widgets() {
global $wp_meta_boxes;
//Right Now - Comments, Posts, Pages at a glance
unset($wp_meta_boxes['dashboard']['normal']['core']['dashboard_right_now']);
//Incoming Links
unset($wp_meta_boxes['dashboard']['normal']['core']['dashboard_incoming_links']);
//Plugins - Popular, New and Recently updated WordPress Plugins
unset($wp_meta_boxes['dashboard']['normal']['core']['dashboard_plugins']);
//Wordpress Development Blog Feed
unset($wp_meta_boxes['dashboard']['side']['core']['dashboard_primary']);
//Other WordPress News Feed
unset($wp_meta_boxes['dashboard']['side']['core']['dashboard_secondary']);
//Quick Press Form
unset($wp_meta_boxes['dashboard']['side']['core']['dashboard_quick_press']);
}

WordPress dashboard items going to disable are:

  1. Right Now – Comments, Posts, Pages at a glance,
  2. Incoming Links,
  3. Plugins – Popular, New and Recently updated WordPress Plugins,
  4. WordPress Development Blog Feed,
  5. Other WordPress News Feed,
  6. Quick Press Form.