Q: How can I find out if I have an iCloud account or not?

If someone has your Apple ID and password, they could create an account (although how someone would get it if you did not tell them is beyond me).

www.icloud.com is the address. If you can sign in, you have an account.

Barry

If that happened you would see iCloud in Settings > iCloud on your iPhone.

Never share your Apple ID and password.

Change your password on a timely basis to prevent your account from being hacked >  Apple ID: Changing your password

Setup a passcode >  iOS passcodes

You can only sign in at that link if you have previously established an ICloud account. I, for example, can sign in to my own but no one else's.

Barry

Your Apple ID may be an iCloud account.  Check at

      https://appleid.apple.com

            Manage your account

  There was a time when an iCloud account was automatically created for Apple IDs.

Then one was not auto created for you.

you can use the same link and use the "Find My Apple ID"

      Enter your First Name

      Last Name

  and current e-m you think is iCloud account

Only enter those 3

     Search for the e-m.