How to secure Apple Account from Hacking?

Here is Apple's guidance on that issue:

If you think your Apple Account has been compromised - Apple Support

You should be aware that changing your Apple ID will compromise your ability to recover purchases made in the App Store. Purchases are linked to your Apple ID, and the ability to update/upgrade apps, subscriptions and such are dependent on that ID as authorization. It isn't easy to escape this or bypass it.

Read this document if you think your Apple ID has been compromised. --> If you think your Apple Account has been compromised - Apple Support

For iOS 15 or earlier, if you want to see if anyone else has access to your device or accounts, click here --> Limit access to your iPhone or iPad - Apple Support

For iOS 16 or later see how Safety Check on iPhone works to keep you safe. How Safety Check on iPhone works to keep you safe - Apple Support

Use the information in this document to check your Apple ID device list to find where you're signed in --> Check your Apple Account device list to find where you’re signed in - Apple Support

Related materials:

Personal Safety User Guide

Personal Safety User Guide - Apple Support

> open the Table of Contents and review the articles

A document with general information about security and your Apple ID --> Security and your Apple Account - Apple Support

Contact Apple for help with Apple ID account security. This page provides country-specific Apple Support contact information ➞ Contact Apple for support and service - Apple Support

Folks using one or a few passwords for everything unfortunately get to have a Bad Day too often. That Bad Day arrives soon after some service somewhere gets breached. Re-using passwords is an accelerated path to doom.

In addition to password reuse, phishing is a common security problem. Password managers and passkeys (and some skepticism) can help reduce exposure to phishing, as the credentials won’t be made available by default on phishing websites. Apple integrates support for both, with Password app and iCloud Keychain and related.

Two-factor authentication enabled is a last chance to prevent compromise, as well.

Above replies have links to much more info.