You're more than welcome to offer day trips to various points of interest and experiences as Extras that guests can purchase. Please note, however, trips that take place off your property are not covered by the insurance policy that we offer. So if you're planning on taking guests off of your property, please keep that in mind or seek additional coverage.
This Journal post is super informative as it clearly outlines what makes a great extra and what is and is not covered by the insurance policy.
Also, check out this FAQ on how to add extras to your listing.
If you have Hipcampers that only want to visit your property for the day, they will still need to book for the night as Hipcamp isn't yet set up to accept day trip bookings specifically. As long as bookings are made through Hipcamp, then day trips will be covered by the Hipcamp Insurance Policy for qualified Hosts as they would be handled the same as an overnight booking.