To find the iCloud subscription follow the steps here: link-> Downgrade or cancel your iCloud+ plan - Apple Support
It does not show up in the regular subscription list.
With that said, you can only be charged for what is shown on your account. If you have more than one Apple ID that has the same payment method added to it, you would need to check the other Apple IDs you may have for subscriptions.
If you are the organizer of a Family Sharing Group, then the charges would show up on the account of whoever initiates the purchase or subscription.
You can also find all recent charges on your account at https://reportaproblem.apple.com. It will list all charges on your account form the last 3 months, including subscriptions and iCloud storage.
There is no way to get charged for things you did not yourself initiate and that are not listed on your account in some way. The system simply is not set up to allow such things. So any charges you may get that show apple.com/bill on your monthly statement need to be tied to an Apple ID and by virtue of the way the system works must be listed there to be cancelled if the are renewing subscriptions.
There's no way to just get random charges.