Frankly, there's no "good" starting off point for a human right now, and that's why I'm not at all comfortable claiming this has actually shipped. It's very much a WIP where only a select few namespaces have actually had a chance to settle.

That said, the maths library might just be the best thing to start with because it's mostly stable, relatively simple, and virtually every other part of the project depends on it in some way. If graphics are more your jam then maybe check out the SDF VM project and associated documents. All rendering goes through a single instruction set that is implemented via a shader pipeline that allows arbitrary scenes to be defined without shader recompilation. The project is essentially multiple compilers wearing a trench coat so there's a little bit of something for everyone... like two fully implemented emulators of the brick variety, including peripherals.

If you're adventurous and want to have your favorite LLM give the project a review in a sandbox then I think that'd be neat! Especially considering that they would have absolutely no problem driving everything themselves through STDIN. Though I totally understand if that's not something you're keen on doing considering the state of things today. Either way, cheers!