For more understanding of cyber security fundamentals, I advise you to read the following:

1. "Cybersecurity for Beginners: How to Get a Job in Cybersecurity, How to Defend Against Hackers and Malware, Coding and Cybersecurity Fundamentals, Hacking with Kali Linux and Ethical Hacking” by Dorian Noris
2. "Computer Security Fundamentals (Pearson IT Cybersecurity Curriculum) 4th Edition” by William (Chuck) Easttom II
3. "Cybersecurity Risk Management: Mastering the Fundamentals Using the NIST Cybersecurity Framework” by Cynthia Brumfield
4. "Cybersecurity Fundamentals Study Guide, 3rd Edition” by Isaca
5. "Ethical Hacking for Beginners: A Step-by-Step Guide for you to Learn the Fundamentals of CyberSecurity and Hacking” by Ramon Nastase