The book by Moritz Lenz is quite good. https://link.springer.com/book/10.1007/978-1-4842-6109-5

There's also this polished three-hour introductory lecture: https://www.youtube.com/watch?v=eb-j1rxs7sc

Combine that with reading up on details in the reference and you're in for a decent start. https://docs.raku.org/reference

If you already know Perl, Raku is easy to pick up. Especially for basic text munging tasks. The RegEx stuff has changed though. Takes some getting used to.

Some of the warts are gone (like a list element needs to have a scalar context, the stuff that scares away beginners).

It is a _large_ language with paradigms and constructs that are from everywhere (ML, Haskell, Lisp, C, Perl you name it).

Powerful operators. Actually too powerful. Easy to write elegant line-noise kind of code.

Easy to use built in concurrency. (There isn't much that is not built in :-) )

Nice language for Sys/Ops scripting if you find Bash too dangerous and Python too tedious.