Once you create/join a movement:

You see who is on the board of the movement. They can give their contact info.
You can submit material.

The material is added like Reddit posts and people can comment.

The key thing though is that people are encouraged to collaborate and meetup.

Next to people's names there are three buttons: Schedule Call | Propose Collaboration | Propose Meetup

NOTE that each movement is like a living publication.

The pitch: magazines are old-fashioned.