Linux

IMO the best thing is to just start using it. You will start to pick things up fairly quickly then. Puzzles don't often ingrain different ways todo things and often focus on weird or niche things that don't come up as often. They can be a nice supplement to not a substitute for just using it in real world usescases.

I do also find it helpful to read the shortcut keys on their site to get a feel for what is available. You won't remember everything but it can be useful to know what is possible. Then when you hit a problem you may remember reading about something that can help and go look it up again.

You could try solving some challenges from vimgolf.com but with helix

I'd recommend not trying to learn all the shortcuts as it's most likely wasted effort. Most people probably dont know the entirety of available moves. Learn the basics to use the editor like, h j k l e w t f g s and start using it. Then whenever you need a ton of keystrokes to get something done, step back and see if there are moves which simplify that. Multiple selections / cursors are also an integral part of using helix so make sure to use em when applicable.

As a sidenote helix isnt very modular imo. The appeal is that compared to e.g. neovim, it is very much a Monolith with most things you need built in which simplifies usage / configuration greatly.

I'll admit that this learning by doing way is prone to adopting half assed solutions but its the only way i know to get comfortable with something quickly

I don't really use helix, but rather emacs with evil mode. For me, the biggest impact came from actually just using it for my tasks. Of course one needs to know the syntax and the commands, but since you say you've done the tutorial, really just start using it for your text editing needs. Soon enough you'll be flying!

Not quite what you were asking for, but there is https://tomgroenwoldt.github.io/helix-shortcut-quiz/

It's quite good for letting you know about things you didn't know you could do, but sometimes it tells me I'm wrong because I'd do it a different way - e.g. I'd go to line 13 by :13 but it wants 13G.

Also, from within Helix you can do space ? to get the list of commands and any bindings they're on.

edit: also, FYI Helix and similar are modal, not modular (although there is a plugin system on the way).

Damn now you got me trying to get used to it. It's hard when vim is so ingrained in my habits. And Helix isn't in the Debian stable repos yet. It does seem faster and better though!