The simplest way is to add the 'author actions' to the single ad listing template. That ads buttons to edit and/or delete llistings. To make sure a listing owner does not have to search too much to find his own listings you can do the following:
- create a page and name it for example 'your listings'
- add the shortcode [gd_listings post_author="current_user" post_type="gd_classifieds" post_limit="6" add_location_filter="0" sort_by="az" title_tag="h3" layout="3" view_all_link="0" bottom_pagination="1" template_type="template_part" tmpl_part="gd-archive-item-list-square" slide_interval="5" mb="3" category="0"] to it
- save the page
- in the main menu create a link 'your listings' that points to this page.
Please note: in the shortcode I limited the number of ads to show to 6. You can use any number.
If you make sure the link is hidden to logged out users you're all set to go.
It is also possible to add a link to the menu of the account of a user, if you want that let me know.