Here, can I speak in Chinese? Because my english is not very good
Hello, I am a full-stack engineer. I am from China. I am proficient in all kinds of programming code, video editing, film and television post-production, etc., and my course will definitely be able to help you.
Absolutely you can create your course in Chinese. But, of course, you are limiting yourself to Chinese speaking students unless you create english captions for all your lectures. That's doable but would require a great deal of work.
Just one word of caution. If you intend to create a course in software development, you are entering a VERY crowded market and you could have a very difficult time getting sales.