Site is gone.

You would need to actually move the files to the root directory for that to work. To get back in you will need to edit the setting directly in the database or edit the wp-config.php file. See here:

https://codex.wordpress.org/Editing_wp-config.php#WordPress_address_.28URL.29

So you need to do this.

define( ‘WP_SITEURL’, ‘http://cierraspostingservice.tk/wp/’ );

Once you get back into the site you can change the settings back to the same http://cierraspostingservice.tk/wp/

If you want to run the site in the sub folder but not show it in the URL you can by following these instructions.

https://codex.wordpress.org/Giving_WordPress_Its_Own_Directory#Using_a_pre-existing_subdirectory_install