The easiest solution is to get hold of a copy of a program like 'Final Draft', or one of the free macro packages that are available for Word or other word processing programs. They'll do most of the formatting work for you so you can concentrate on the story.
Also, frankly, provided it's in basically the right format, if the first few pages of your script grab the reader and the rest of it is great, few people are going to turn it down just because the margins are 1/4 of a inch out or you didn't capitalise the right things.