This is the new format for downloadable resources. All they are as posts that you have marked with the category “Resources”. Each resource download page is now manually created with a graphical editor, just like any other post. But you can use existing resource pages as templates, simply duplicate them and begin editing.
Make sure you take care to set up your preview image appropriately.
The block that shows the title of the document and the download button is a media block. It takes care of all the hard work for you, just select the media file using the block controls. On the front-end, the Download text turns into a Download button in the stye of the theme.