https://www.hackthebox.com/
The #1 cybersecurity upskilling platform.
Hack The Box gives individuals, businesses and universities the tools they need to continuously improve their cybersecurity capabilities — all in one place.

https://tryhackme.com/
TryHackMe is an online platform that teaches cyber security through short, gamified real-world labs. We have content for both complete beginners and seasoned hackers, incorporation guides and challenges to cater for different learning styles.

https://portswigger.net/web-security
Free, online web security training from the creators of Burp Suite

https://academy.hackthebox.com/
Master cybersecurity with guided and interactive cybersecurity training courses and certifications (created by real hackers and professionals from the field).