In order to be able to submit your own initiative you need to register to the site first and then login. Use the Initiatives > Register menu link to register to the site and then login here or using the login module on the right.
Clicking the Initiatives > Add initiative menu item takes you to a form where you can add your own initiative.
Clicking the Initiatives > My Submissions menu item takes you to a list of all your submissions with the option to edit them again.