I have started learning narrative a

I have started learning narrative and descriptive composition for a full term. I've learned about writing narrative and descriptive writing that should do. From the moment of writing, brain storming, writing, Introduction, conclusion and how to properly write the grammar and parts of the article. It is difficult for me. I'm trying to write my best. But all that I sent. I got back to all the time because I wrote it irrelevance and my grammar is very weak. I try not to write fragment and run-on, but it is often found in the writings of me.