I’m using the Hotel Booking plugin on the Twenty Seventeen theme. If I click on amenities to read their description, the title and description of the selected amenity show on the top of the accomodation type page.
Can I change this so that it shows under the amenities list?
Do you mean right below the amenity on the same page? Such changes would require plugin custom development. For now by default the amenity link opens the page with all the accommodation types, which have the same amenity applied to. The title and description is displayed at the top of the page as for any other standard WordPress post type, as the Amenities itself appears to be a custom post type.