Woohoo!
-How hard is the subject?
Depends (I know, not a very helpful answer).
It's not a subject where you can rote-learn everything. You have to understand the key concepts, and this can make it difficult for some people. That said, once you do understand the concepts, it becomes much easier. You don't have to do endless practice questions or exams to do extremely well.
-What sort of person would be interested in this subject?
If you're curious about what makes the world tick, you'll find this interesting.
-What do you learn in this subject.
How micro/macro economies work. This is probably the most practical subject in VCE. The things you learn will help you later on in life regardless of your career choice. Want to buy a house? Get a job? Invest in the stock market? Buy stuff from ASOS? Economics will help

Sam