Regarding the featured trip query, you can definitely display the featured trip in the sidebar. For this you can simply add the widget “WP Travel: Featured Trip” in your desired widget area. You can also display the featured trip through the use of shortcode in page/post.
In the inquiry form using the shortcode. If the user fills the form with selecting the trip, he is not alerted when filling the form. After pressing submit he gets a very cryptic error message. https://tinyurl.com/yxkkmcuh
Actually since its an enquiry for he should be able to send the form without selecting trips (make it optional) or allow to add something like ‘custom trip’ in the drop down
Please once place the short code in a new and fresh page and verify the issue. As mentioned early, in our side short code is working perfect and hence, we are not able to replicate the issue in our side.
Also, make sure the issue is not because of the conflict with any third party plugins by deactivating all third party plugins.