When the begin the screenwriting process, always ask yourself the why: Why does the character ask to be in a story? What is it I feel about him or about her? Because then you begin to find out why you want to write the whole story, and what the passion of that character is, and why he wants what he wants.
Eventually you reach the moment where you can dream for your character, where you can remember for him or her everything that happened in his or her past. When that happens, then you are safe because the character (not the screenwriter) will find his/her way towards the resolutions of the story.
At this point, the problem is how to hit that character in his most vulnerable spot. How to put him in the worst predicament imaginable. How to strengthen that predicament, and how to increase, at the same time, his desire to achieve his objective.
Once you get that, you’ve got a story growing, and there is no problem what to do next. You just use the rational approach and start asking yourself: What are the sequences in which this character tries to get himself out of the predicament? That's screenwriting!
And you put him in that predicament. Then you have the steps from the set up of the dramatic situation to the culmination. When you can see the sequences and you start asking what event you can put in the center of each sequence, the story begins to unravel and then you have a chance to feel quite safe. You begin to have an outline, and after that, you can begin to write your screenplay.