Happily! Have you tried out J's labs? That's what I usually recommend, just because of how varied, deep & consistent they are. If you have, and they didn't work for you, I'd ask if you've read J for C Programmers, which is a useful book if you're having trouble with the paradigm overall.
J is in an interesting spot because it's a bit more complicated than K (though, I'd argue, less complicated than modern APL2, which won out), but has learning resources that actually help you get a feel for the language.
And of course, check out idiom libraries, they sometimes help to make things "click."
(J Labs can be found in every J install; there are some pieces that only work when you have Windows, but overall they work anywhere a computer can be found, and the ones requiring Windows aren't really essential to learning.)
Perhaps it would help you to start with K (e.g. https://github.com/JohnEarnest/ok is free, has a web repl with interactive graphics and stuff)
In a way, K is a cross of C and APL; K is the essence of APL minimized to the absolute minimum usable subset, even though less pure; e.g. complex values are not part of the language, and matrices only as vectors of vectors (unlike APL/J where you can have either). It also does away with user defined operators and a lot of other stuff.
