No one can teach writing, but classes may stimulate the urge to write. If you are born a writer, you will inevitably and helplessly write. A born writer has self-knowledge. Read, read, read. And if you are a fiction writer, don't confine yourself to reading fiction. Every writer is first a wide reader.
I think a fictional invention grows according to its own development, not the author's. Characters in fiction are not simply as alive as you and me, they are more alive. Becky Sharp, Elizabeth Bennett, and Don Quixote may not outlive the burning out of the sun, but they will certainly outlive the brief candle of our lives.