unable to link my custom content type nodes to a menu I created
By default, Drupal 7 does not create a filtered list of content. You're going to want to use Views Page to create a list of content.

Delete the menu item you created, then install https://www.drupal.org/project/views and its dependency https://www.drupal.org/project/ctools

If you have Drush installed...

drush dl views
drush -y en views views_ui


In your browser, go to /admin/structure/views
Click "Add new view".

View Name: Photos
Show [Content] of type [Pics]
[X] Create a page

Page title: Photos
Path: pics
Display format: Table

Click "Continue &amp; edit" to customize



For information on Views, see https://www.drupal.org/documentation/modules/views