iCloud is all part of the wider Apple ID environment.
All apple devices need registered against an Apple ID, there would have been an option to opt out of iCloud.
First of all I suggest we get your Apple ID \ iCloud account in good standing so you can access your e-mails then proceed to disable the iCloud functionality.
To do this, its best done via a remote session and over the phone.
Please let me know a suitable time when I can give you a call and connect to your machine.