You can create a team project and add the AE file you want to the team project by dragging the AE file into the media browser. You can then open compositions from that folder.
Media Browser meaning Project panel, where you can drag your footage and stuff into the timeline. This panel:
When making a team project, just add collaborators by clicking "Edit" when creating the Team Project and adding email addresses.
Would you like to be a Collaborator?
No not really lol, just invite your team members there.
If your looking for team members, then start on some sort of social media like reddit/discord. i dont really know how to get a team lol