@Marissa160 Whether to leave a review response or not depends on the review the guests leave. Sometimes hosts fully expect a bad review, only to be surprised that the guests left a nice one.
Sometimes the guest's bad review is so off-the-wall and such an obvious outlier among all your good reviews, that it doesn't even bear responding to- the guests come across looking like crazy ranters, and no one will take the review seriously.
Other times it feels necessary to correct lies and misinformation for the benefit of future guests. Keep in mind that responses appear on your profile, not the guest's, so they shouldn't be used to speak directly to the bad guest, but only clarify misinformation. They should be brief and non-emotional. Also never mention anything in a response that the guest said to you privately or in a private message. Only address what is stated in the review itself.
If you are ever unsure what kind of review or response to leave, you can ask other hosts here for feedback on a draft (or just say "Hey guys and gals, could you take a look at the review from XX on my profile, and tell me how you would respond") , but just make sure to post it in the "Host Circle" section of this forum (not the "Hosting" section), as only hosts have access to that section. The Hosting and Help sections are open to both hosts and guests and even someone who just joined today.