Articles are not displayed in the main menu.

There is a problem:

I created themes in the "main menu" (by creating a "Basic page" or "Article" and specifying in the settings to add a link to the main menu, after which the link appears in the main menu).

However, I cannot add articles to these links!?

I can only add articles on the homepage if I specify the "Publishing options" - "Place on the homepage" in the article settings.

How can I make it so that I can leave articles or other materials under all items in the main menu?

I also created links in the menu by going to Structure - Menus - Main Menu - Add Link, but another problem arises: what path should I enter in the path field? I tried different paths and encountered errors like "this path cannot be created" or the path was confirmed, but when clicking on the menu item, it led to a page stating that such a page does not exist, etc. 

Sincerely, Alexander!