How do I add Chapter titles to compiled MS?

This is my initial post in the forum.

I can compile a lengthy doc well enough to get the basics looking the way I want.

But the separated “chapters” don’t have Chapter Titles or Chapter numbers.

Which is probably due to how I structured the work.

I have just one CHAPTER in the binder. All the sections that I want to be chapters are formatted as Files.

First then: how do I convert the files to chapters in Scrivener?
Second: will that likely take care of the naming of chapters in the compiled version?

Thanks