Need CONFLICT for my story...!?

I do believe that the best way to write a story is to actually have an idea and then create the characters. I say, keep those characters in mind, sure, but don't try to force a story out of them. Keep imagining in your free time, and reading other stories, and watching the news, and studying history and one day an idea will come to you. You'll find that some of the characters will fit quite nicely with it, while others will not, at which point you should not try to force them. Forcing a story from characters only creates a shallow story with no depth or meaning. They start seeming to specifically exist only to help the story line progress, which should come naturally in the writing. Have you ever seen the movie Shark Boy and Lava Girl? Kinda like that. That movie only existed to give those characters an existance.