Sorry for the late reply.
The course is designed to be flexible so learners can adapt the lessons according to their needs or learning style.
However, we tend to recommend listening to one or two Interactive Audio lessons and then one or two Language & Culture lessons as the lessons often relate to each other. Once you are relatively comfortable with the language, you can try using the MegaGames software to solidify your learning and get more practice. As you work through the course, try doing a few Survival Kit lessons - these are not in any particular order however they contain bonus lessons with important vocabulary that you will find useful throughout the course like colors, days of the week, etc.
For extra practice, check out the "Practice" tab in the Interactive Audio lessons. You can also rate all your lessons using the My Level feature - for more information on how to use this, please watch the TOUR video in any lesson.
If you are short on time and don't need to know the breakdown of the language, you can just listen to the audio lessons as these will already give you a good grounding of the language. If you can spend a bit more time on the course, definitely give the Language & Culture lessons a go but like Bob says, try not to get too stressed out with the particulars of the language!
I hope this helps. Good luck!!