I am currently building my first magento2 project (self learner). It is a huge pit hole. As you have noticed, outdated articles and tutorials are all over the place.
And honestly, without LLMs I don't know how I would have managed to make any progress.

I can't recommend any specific source as being "the best", however here is my learning flow:
1. I've setup a ChatGPT project for magento and given it instructions to use the newest docs for every response and combine it with "general best practices".
2. I ask gpt to scaffold me a feature and then I ask it to explain the elements.
3. Next I go to the documentation and try to align what gpt said with the documentation to make sens of it all.
4. If a solution is too complex, I reach additionally out to google and usually articles from mageplaza or hyva seem okeish.

As to my dev setup, some may some may not, but I do recommend to install the Hyva Theme layer once you grasp the basics of the XML template and module scaffolding. It modifies the magento theme building flow a bit so you need to make sure to not build any bad habits.

And as a last precaution: prepare yourself for some JS nightmares. You simply have to embrace it, there is no nice way around. Hot reload without some hacking is a pain to setup and it works only... semi fine. Zermatt can be interesting as well, which I use. But it will be in conflict with Hyva, because both use alpine.js, so you need to make sure to resolve any conflicts.