Do you mean how do you figure out how much to charge, or are you asking how to get into the calendar and change the rates, @Mario878 ?
If you mean the latter, go to the calendar tab in your dashboard when you are signed in, click on the day you want, and when the edit box appears on the right, scroll down to Nightly Price and change it. Then click Save. That's on a laptop. On a phone, you have to tap the date and then tap edit.