AWS has a multitude of different offerings with confusing pricing structures. They have zero incentive to make them understandable.

That said, chances are your new company has people who understand this already and know how to manage it. Hopefully, they'll put up some guardrails that prevent you and others from running up a big bill. I wouldn't expect a junior programmer to know how to do this, but that's ok as long as the company is managed right. Granted, that can be a big if sometimes.