Setting up non npm / gup site. Layout is a mess out the box.

The css and js files in assets have loaded but the layout of the site is wrong and looks nothing like the screenshot on the front page of this theme project (attached as well) out of the box. I've watched at least four videos for this module in particular but there is very little support for those who cannot or dont want to use npm / gup. Furthermore most of the videos focus on color picking instead of the proper way to customize the layout of the site (at least starting off).

Can better documentation be provided on "do's and don't" for people who arent using npm? The package on the uswds site has a lot of files and folders in it but how (packages in particular) can the data pertain to Drupal?

I have loaded all the css and js files and see them in my source but the layout is just top down what looks like no styling applied. Is this the way it's supposed to be from the start and you have to customize it all yourself or is the example theme (screenshot attached) the way it's supposed to look by default?