Also, a thing about writing outlines: It is a bit like a Coloring book. You have an outline. All you have to do is fill it in. You pick the colors and the shades, you get to decide where to leave it empty.
You also don't have to do it linearly.
There was this page I read on writing screenplays a while back. It taught me about the 8 film reels. And the beat draft.
Now before you know that you have to understand a three act structure, dramatic structure, and it's good to know the hollywood formula(though not important)
If you already have an outline good. Hopefully it follows the regular structure of Beginning Middle and End. Or Intro, Complication, Climax, Resolution. There are bunches of other ways to do it.
https://upload.wikimedia.org/wikipe...s_pyramid.svg/1280px-Freytags_pyramid.svg.png
What the beat draft was nice is it is pretty free form. You just take your outline and write a few paragraphs about a very basic idea on how you want each part to go. A kind of non formal fatter outline to help you get the beats down.
The 8 reels was an interesting concept. Film reels generally have a finite length in terms of minutes. A Film reel is generally 1000 feet which is 11 minutes. In an 88 minute movie there are 8 reels to be thrown on a projector.
Generally, when writing a screenplay in screenplay format 1 page = 1 minute of film time. This is not exact, but it is a good rule of thumb. So, really you just have to write 8 chapters that are 11-15 pages a piece.
So start with an outline. Break that outline into 8 chapters. Get the ideas you want into 8 paragraphs in the beat draft. Expand each beat into a 11-15 page chapter. Then edit, edit, edit until your script is real tight. Now you actually don't want all the chapters to be an even 15 pages. Working on pacing is going to be a difficult task, probably the hardest task, but now everything is fleshed out.