Well, please tell me specifically when you have doubts to create a course.
Since creating a course involves many things.
To publish it, you must register as an instructor on the udemy platform,
upload the videos and complete what is requested.
It is also important that you meet standards such as 720 video quality and good sound.
As Alvaro suggested, it is not clear whether you are asking for help on creating a course (like your question's title says) or publishing a course you already created (like your question's text says).
The teaching center is a great place to start. There are lots of information there.