Not too easy. Not too difficult.
It is a core subject. Every student learning computer science must thoroughly know the data structures being used in the real world. It is a foundation and without it advanced studies in the stream can't be made effectively.
You learn how data is stored, not physically, but structurally. After taking the course you'll be able to decide if you want to store variables in an array, a stack, a queue, a list, a tree and so on.
Hours per week:
Advice for students:
Just understand the concepts. Do not try to mug up as this is a core subject and you're not just doing it for passing the course.