There’s plenty of how-to information and lots of exercises and tools on the Internet and also in bookstores and places like WritersStore, which has training courses on DVD and all sorts of other aids, mostly but not exclusively oriented toward screenwriting. You can also find writers’ clubs, critique groups, writing classes through adult ed., and so on. Blondesjon is right, you must have that inner drive (and talent), but there is a lot of help available.
It would not make sense for Fliutherfolk to try to put it into a posted answer.
What we can do is cheer you on. There’s a thread for posting your goals and progress right here. Scroll down to the bottom for recent weekly postings.