10 years in webdev. How do I learn cybersec/white hat hacking?

I am long time HN user, but this is a throwaway accout. I know this might sound a bit naive but after watching Russia bully the world and then launch a full-scale invasion of an independent country, I feel like I would like to do more than just donate money. I've been doing webdev for over a decade, and I have some fundamentals in web sec, but I would like to go beyond that. For example, I would like to confidently help smaller NGOs and political think tanks to fend off Russian/Chinese/etc cyber attacks and threats. What would be the most optimal way to self-educate in this are? I have some free time to invest, but not as much as when I was a teenager/student and could play around programming and experimenting with technologies. This time it has to be more structured.

I would appreciate any ideas, but especially from someone who went through something similar.

Thank you