Does wordpress support “consumer-users” natively? Or I must do it by means of a plugin?
They’re just users, you don’t need to be able to edit pages to be logged in. In fact if you create a user, their default role doesn’t allow them to even see the pages and posts menus.
All users in WordPress have a role, the basic role subscriber allows a user to reach the WP Admin area but the only thing they can do is edit their profile. Many plugins use this and redirect visitors from WP Admin to the frontend if they try to go there, giving them a frontend user edit screen and a frontend user login instead.
I’m not talking about the “word-press native users that will be able to edit pages”.
Then don’t give them author/editor/admin roles
I do not want the users to publicly register themselves. I will manually add the users after talking with them and let them they have access.
This is a checkbox in the settings screen.
I need to create a small members area, probably for about 1000 users, not more.
I strongly recommend searching and evaluating membership plugins. The ability to login as a user as you describe is already a core part of WordPress that’s relied upon by e-commerce and member plugins powering millions of sites.
If you’re adding users manually, you could even do it via private pages, though that wouldn’t handle your other requirements ( and you will need to seek recommendations for those requirements elsewhere ).