17 platforms where you can begin cybersecurity:

1. HackXpert - Free labs and training.
2. TryHackMe - Hands-on exercises and labs.
3. CyberSecLabs - High quality training labs.
4. Cybrary - Videos, labs, and practice exams.

5. LetsDefend - Blue team training platform.
6. Root Me - Over 400 cybersecurity challenges.
7. RangeForce - Interactive and hands-on platform.
8. Certified Secure - Loads of different challenges.

9. Vuln Machines - Real world scenarios to practice.
10. Try2Hack - Play a game based on the real attacks.
11. TCM Security - Entry level courses for cybersecurity.
12. EchoCTF - Train your offensive and defensive skills.
13. Hack The Box - Cybersecurity training platform.

14. Vuln Hub - Material for hands-on experience.
15. OverTheWire - Security concepts via challenges.
16. PentesterLab - Learn web-app penetration testing.
17. PortSwigger Web Security - General learning.

If you're looking for a specific roadmap to learn cybersecurity, follow this:

https://danielkelley.me/cybersecurity-roadmap/