To change organization, log out or see your name in the organization you can go to the profile page.
Press your letter symbol on the left menu. Here you will see your name, your e-mail and the log-out button. To see the organizations you are in, press the organization name and all organizations will be listed in a drop down menu.
Open the settings page by pressing the settings button on the top right corner. Here you can see your name and e-mail, check your organizations, log out and contact support.