No one can teach you exactly how to write. Each person approaches creative writing differently. Every writer has his or her own method. I usually have a character or story idea inside my head for a long time (sometimes years) before I actually begin. I know where I'm starting and where I'm going but I never know what's going to happen in the middle or if the ending will be what I imagined on the day I began to write. It's the surprise that makes writing exciting for me. Other writers know everything before they begin. They make detailed outlines or have it all worked out in their heads before they put a word on paper. There is no right way or wrong way. There are a hundred different ways to tell the same story. Whatever works for you is okay.