exercises here at cookie are assigned *after* the prerequisites for completing the exercise have been addressed. the courses have been designed in such a way that the exercises are an opportunity to apply what you’ve retained from watching the videos; if you are unable to make ends meet I recommend saving your project file, closing Blender, and rewatching the course material to broaden your understanding of the course material.
Personally, I have to watch the course material several times before I am able to cement the workflows into my foundation; paying for something doesn’t mean you no longer have to apply effort. use the forums too! there are a ton of helpful community members here who will be happy to answer questions.
Derek