When you're writing a screenplay, it's important to get the reader hooked somewhere in the first 10 pages. As a reader, we want to know as much about the protagonist before the inciting incident occurs so we know who the protagonist is as a person, and why we should root for them throughout the film. When it comes to expanding their ordinary world, there's a few things you'll want to include.
PROTAGS POSITIVE AND NEGATIVE TRAITS
Everyone has positive and negative traits. When you're creating your characters positive and character traits, show at least three of each. For example some positive traits could be: helpful, leader, humorous, brave, daring, outgoing, and so on.
Negative traits, however might be: hangs out with the wrong crowd, rebel, snotty, rude, selfish, and so on.
Let's take a moment and examine Dorothy Gale from The Wizard of Oz. In the first 10 minutes, we can see that she's caring and good to animals. We also find out that she's desperate to others and will do whatever it takes to ensure the safety of those around her. Although she's a bit naive at first, Dorothy becomes more assertive, enduring obstacles with her newfound friends and helping them achieve their goals before she reaches her own.
FATAL FLAW
Believe it or not, everyone has a fatal flaw! Without a fatal flaw, it would be easy for your protagonist to reach their goal in the end. Unlike their negative traits, the characters fatal flaw is what holds them back from reaching the end goal and they don't overcome it until the start of Act 3. Usually hinted in the Opening Hook, the protagonist is repeatedly tested throughout the film based on their fatal flaw. For example, Rocky Balboa thinks of himself as a loser who cannot go the distance in the boxing ring. ("You're fighting like a bum!")
NEEDS AND WANTS
What a character needs and wants are two different things. A need is something internal. It's what they need to learn about themselves, for them to grow and ultimately fulfill their want. The protagonists wants, on the other hand, are external. It's what drives the plot forward. Let's take a look at Silence of the Lambs for example. Clarice wants to stop Buffalo Bill, but needs to overcome the ghosts of her past and gain respect as a professional in a man's world.
I'm sure there's other things you can add into the characters ordinary world, but you don't want to show too much in the first 10 pages because your main focus is just providing whatever valuable information you can in that amount of time. As the film goes on, you can continue to expand on the ordinary world and show us what their world is like. When I took screenwriting in college, my instructor would go in full detail about other things that "should" be in the ordinary world, such as the characters living situation, occupation, and other things, but personally I think what I covered in this blog is what I would consider important information. Sure you can give them dreams and fears, those are nice to have as well.