Whenever you want! It is a completely self-paced. Once you have paid to create the course you can take as long as you want to input and create the material for it. We suggest that you have some procedural framework in mind for uploading material, and marketing your courses to shorten the time curve. 

Your length of time to create courses is determined by the subscription for that course. If you pay monthly to use HOOL tools and to host your course then you are month to month for that course. For payment purposes each course is independent of any other course regardless of if the courses are interdependent. 

You have 7 days from the time you created the course and paid for it to seek a refund. You can use your administration panel in HOOL or confirmation email you received confirming payment to apply for a refund.