[beagle3]

I learned APL on a mainframe over 30 years ago, which is not something I'd recommend (also, you're unlikely to have access to one), but rumor says Dyalog has good tutorials, such as "Mastering Dyalog APL", see links here https://www.dyalog.com/getting-started.htm

As for K, Stefan Kruger's text seems like a good introduction https://xpqz.github.io/kbook/Introduction.html

[yakubin]

Thanks. Will check these out.

[skruger]

I’ve written a few things on APL and K for the learner. Links here:

https://xpqz.github.io/about/