You are asking the right questions at the right time. Before you create a Udemy course you have two tasks. Use the Udemy tools to determine what course topics are in demand and are under served and do research to find out what specifics potential students want to learn. You design your course to match your interests to the interest of potential students. A third task is to explore the marketing area of this Community AND the technical constructing of courses. After that, come back with specific questions for fine tuning and you should get the answers you need. As for income, at the moment that is impossible to know. People say it is a long term effort for success and I think that is true.
Robert Brown, Ph.D.
Unique insights for personal & business success