This is what I have done:
gem install jekyll bundler
jekyll new staticwebsite
cd staticwebsite
jekyll build
What I get is this:

It is not clear to me what is missing.
This is what I have done:
gem install jekyll bundler
jekyll new staticwebsite
cd staticwebsite
jekyll build
What I get is this:

It is not clear to me what is missing.
On
When you check your _config file you will see that
theme: minima
and that mean your jekyll use minima gem and to locate the file of minima theme use the command bundle show minima
to get the path of minima and open the file location to see the files that will use in your jekyll site

For more information check Jekyll Themes
Since Jekyll 3.2.0 gem based themes are the default, this is why you are not seeing all the typical structure that used to be before them:
That basically means that by default you won't have these typical directories:
But Jekyll will use the ones in each theme, unless you overwrite them or copy to your jekyll instance to modify them.