Apple has posted a support document explaining just how to check the personal privacy settings on your Apple devices. As they say:
If you’d like to revisit what you share with other people, or restore your device’s original settings for any reason, this guide can help you understand what information you are sharing via your Apple devices, and how to make changes to protect your safety. It includes step-by-step instructions on how to remove someone’s access to information you’ve previously granted: from location data on the Find My app, to meetings you’ve scheduled via Calendar.
If you’re concerned that someone is accessing information you did not share from your Apple device, this guide will also help you identify risks, and walk you through the steps to help make the technology you rely on as private and secure as you want it to be.