Q:

Page handling, good practice

I have created a navbar and, as far as I can realise, I have to create a component for each page and subpage. And if you have a lot of navigation options with sub-navigational options for each, like shown in the picture, then it seems redundant to create a lot of components. 
https://imgur.com/a/9uTLbhu
Is it really necessary to create 20+ components? What is normal Angular structure and how do you handle?

A:

Yes, it is a common and good practice to create component for each page.
In case you serve content depending on a parameter (in your case it looks like an url parameter), you can configure route to take in a parameter:
{ path: 'article/:articleId', component: ArticleComponent }

then, in the component do:
constructor(private route: ActivatedRoute) { }

ngOnInit() {
  this.route.params.subscribe((params) => {
    // get your article with id params[articleId]
  });
}

this will help you with parametrized routes.
You can use this to create page 'Portfolio', each subpage will then redirect to the same component with different parameters (Webdesign, Graphic design, etc.)

