I am not the person you asked the question of, but I took a creative writing course in college. Like any other course, it is a combination of reading other's material and writing your own material.
You read the works of professionals and other amateurs. You try to learn from their nuances and tricks of the trade, without completely copping any one person's individual style.
In a class setting you get to critique other classmate's work so it forces you to focus closely on what is right, what is wrong, and what you would personally do differently. In return others critique your work.
You also are assigned various projects. You can come up with your own, such as:
Write three poems this week. If you would like more specific suggestions for poems, write one on love, write one on nature and write one on existence.
Write a three to ten page science fiction story in a third person perspective.
Write a three to ten page story ground more in reality that deals with a harsh subject matter from a first person perspective.
Write a narrative about a time you felt great fear.
Also, keep a daily journal about anything on your mind. The important thing is to keep writing.