What is a course? In technical terms it’s considered a unit of teaching, in more practical terms I just see it as content. Text content, image content, video content, quiz content, etc. When it comes to planning your strategy for creating a course the content comes first. That content must be well organized in a manner clear enough for all people to understand. People who will have to write, edit, or otherwise work with the content.
I won’t tell you how exactly to create your content but I can try to help you keep everything organized. Good organization reduces issues. Issues that will arise due poor and unclear communication usually caused by poor organization. Since my role is in production I see these issues all the time.