A Babbel subscription gives you access to all courses in your chosen language. You can change your course whenever you like.
On www.babbel.com, all available courses can be accessed via My Level and More Courses in the main menu at the top of the screen. Just choose a new one, and that course will then be shown on your Babbel homepage. To display the full list of lessons, click on the View all button below the third lesson.
With an Android or iOS app, you'll find all available courses in the app's menu. Tap on Courses, and then on the arrows/menu at the top of the screen, and select a new level/ course.