Let user publish posts on community page

I want to create a theme that lets the user publish posts (or all posts in an entire category at once) on a certain WordPress page.

The user should be able to write and edit those posts and if one feels ready, there is a button that allows to publish the post not only on ones own page, but also on a cummunity page, where all these articles flow together and can be voted.

I don't know if and how this could be done and would be thankful for any hint into the right direction.