I find macroeconomics fascinating. These theories to explain how growth works, what incentivizes it, where value comes from, I find them really fascinating.

It kind of echoes a common theme with LLMs, of humans creating systems that somehow work and only afterwards trying to make sense of why they work. We know that transformers are good at capturing context, and gradient descent is good at arriving at a working model of that context but how exactly this knowledge is being distilled and stored in an embedding space, no exact clue.

Is there some course which teaches the basics of macroeconomics?

You can start with a used copy of an older edition of mankiw’s text which is a standard undergrad reference.

Barro also has an old undergrad macro text which is good

The gap between undergrad macro and professional macro is extremely large. That shouldn’t dissuade you it’s just a note.