Hello @Marie459,
You can change your price like this.
Click on "Host" and then on "Listings".
Then click on your listing photo.
Click on "Pricing".
Then click on the "Edit" button for the "Nightly price" section.
Click in the "Base price" box and enter the new price.
Then click on "Save".
This price will apply to all dates unless you set different prices for weekends, festivals etc.
You can also set a different price for any date by clicking on the date on your calendar.
Steve.
Steve.