How to delete files from my icloud

You can delete files saved from apps in the Cloud, and you can delete files saved in iCloud Drive.

First, saved files from Apps, go to: Settings > Apple ID > iCloud > Manage Account Storage

You will now see a list of the apps that have stored content in iCloud. From here you can choose to delete or keep.

Second, find files in iCloud Drive. Open the Files app and select iCloud Drive. Everything you see in iCloud Drive is in iCloud. You can again choose to delete or keep what you need. Finally, remember to empty the trash in Recently Deleted. Please note that once this is done, the files are NOT recoverable!

You can read more about how to manage your storage space in iCloud here:

Manage your iCloud storage - Apple Support