To join a project, select a project from the list (Project management > Projects) and click on the Join project button at the bottom.

Alternatively, you can always find the Join project option in the project sidebar in the "More actions" tab.

If you decide to leave a project, this is the same place you want to go to.

If you're not an Admin, Manager or Coordinator, and need to join a private project, you need to be added to the project by the project manager or an admin.

Admins, Managers, and Coordinators will be able to see and join both public and private projects. Private projects are marked with a lock icon on the list.