> I've read about KGS but I've never figured out how to engage with it.

Just download CGoban, here is the website:

https://www.gokgs.com/

Most of us started who are still active on the server have been playing there 20+ years at this point. E.g. I myself (and many others) started playing after reading this article:

https://tromp.github.io/gostory.html