Yes, currently there's no way to jump to the middle of a course. That lets us keep the lessons shorter, without needing to recap earlier topics. We're planning to add a way to skip, but that's not in yet unfortunately.
Edit: Just to be clear, all of the lessons shown on the course page are available, but you have to start at the beginning for now.
Edit: Just to be clear, all of the lessons shown on the course page are available, but you have to start at the beginning for now.