archives.php?

1. You should never ever access a template file directly – i.e. by putting its name in the address bar. They are for internal use in the theme.

archives.php (with plural S at the end) should be a Page Template (read the Codex) and should be used when creating a new Page and selecting it as the template for that Page.

2. yourdomain.com/test

@moshu: hmmm…

to 2) I can not access my page titled “test” via domain.com/test! I can only see it when I type https://domain.com/?page_id=xy!

Do I have to include something into my .htaccess maybe?

Thanx anyway!

Greetz,
lynx

Sorry, you are right: the URL you posted ALWAYS works.
The one I assumed – is valid only when your “nice” permalinks are activated.

So, I can always access this page via https://domain.com/?page_id=xy, but when I activate “nice Permalinks” i can access the page via

domain.com/test

or domain.com/archives

it depends, how I named my page, is that right?

Basically, yes. The “slug” is created by WP from the title of your posts or Pages.
https://codex.www.ads-software.com/Introduction_to_Blogging#Post_Slugs