Firstly, try to get a genre or area of interest. I personally looked at my life and found an incident that I can use for a story if i manipulate it to fit what I want my movie to be like ... the simple can be the successful. Don't try too hard, what comes to you freely is usually the best to be...
Just a question: What do people think of iMovie for editing? Isit good? I used it for a movie in Drama for year 10, but nothing serious, so never bothered tweaking and that. SHould I get that or something else?