Hello @ginake13,
First of all thank you very much for using the WP Trave plugin.
Regarding your query, yes you can add the trips without displaying the prices. For this do not enter the price in the pricing field and save the trip.
As for removing the filter, WP Travel has already provided the filter using which you will be able to remove the mentioned field.
To know how to create and activate the child theme refer to below-given link:
https://wptravel.io/how-to-create-a-child-theme/
After activating the child theme in your child theme functions.php file add below given code.
function wp_travel_remove_filter_by_price(){
return false;
}
add_filter('wp_travel_post_filter_by_price','wp_travel_remove_filter_by_price');
Hope this helps.
If you have any issues further then kindly post them in our official support forum below:
https://wptravel.io/support-forum/forum/wp-travel/
Thank you.