@Sara343: I recommend as a new host you turn the INSTANT BOOK feature off until you get your feet under you. See how you and your guests interact at inquiry, during a stay and after check-out. Once you feel comfortable hosting and the INSTANT BOOK feature is something you want to do then go for it.
Any booking no matter if its through instant book or a typical reservation will always give the the option to review. You review the guests, the guests review you. Not every guest will leave a review.