Getting started with Core Data

I am having trouble understanding how Core Data works conceptually and in terms of code.

I get that there is a coordinator and a context. I also get that there is state management. How do they work together?

I don't understand how I can store, say, an image and a few strings as an object.

Let's say I want to retrieve the image and the strings later. What do I do?

Where do I save my state? How?

What does my code look like? I would really appreciate a bare-bones code sample here, because I'm really confused.