@Roberto1477 Why does your Airbnb calendar have open dates when it's not available? Do you book through other platforms or privately? If so, as Linda said, you need to sync your calendars so this doesn't happen again.
You can certainly change to Request to Book, but if a guest requests dates that show as available which actually aren't, you will then have to decline their request, which isn't as bad as cancelling, but if you decline a lot, you may be suspended eventually, so it's important that you get your calendar under control no matter what.