@Aleksandra207 That "nightly rate adjustment" indicates that you offer a discounted non-refundable cancellation policy, or other discounts.
Airbnb also applies a 20% discount to the first three bookings on new listings by default, which you can turn off. Check all of your discount settings and cancellation policy.
Your listing is not set up correctly, and you should snooze it right away before you get any more bookings.
If you are renting out 4 private rooms separately, you need 4 listings, one for each room, with a guest count for that room only. You show that room only, plus shared areas, on each listing. Right now, I could book all 4 bedrooms for 4 people for the cost of one room.
Also you need to work on your listing description. I would have no idea what you are offering- you haven't described the guest accommodations at all, the house layout, who the guests are sharing the home with, or anything. And why is there a photo of a clothes rack full of clothes? It should be empty of anything but hangars for the photo.
And once a booking is confirmed, you can't change the price. Changes will only apply to future bookings.