Final Draft and Movie Magic both have an included collection of current templates for screenplays and TV shows by name. They are updated regularly (for legal / registered copies) as new show formats are added.
The non proportional type face 12 point courier was the standard typewriter font and what has historically been used as the timing estimate of one minute per page for feature scripts. This can be less accurate for some TV shows.
Readers and execs do not look kindly on your script when they don’t find and you’re not following what they expect to see on the page. Messing with any combination of font size, margin measurements or line spacing is / are a reason why a writer’s months or years of work end up in the round basket. Trust me, an experienced reader can tell at a glance.
If you are in Los Angeles or New York the library at the Writer’s Guild has both a current and historic collection of scripts you can read but not check out. The AMPAS (OSCAR) library on Fairfax Blvd south of Wilshire Blvd in Los Angeles has the same review only arrangement for their collection of the OSCAR award winning scripts.
Disclosure: I have copies of and teach using David Trottier’s Book and Final Draft. I receive NO commission or other compensation from David Trottier, Final Draft, Write Brothers, Amazon or the Writer’s Store on the sale of The Screenwriter’s Bible, Final Draft or Movie Magic.