The most important thing you need to do is introduce your character, and get your audience hooked onto them as early as you can! Let's take a look at the following example.
INT. PENTHOUSE - NIGHT
GREG, 40s, wearing a suit, enters the room, and hangs his jacket on the coat rack. He heads over to the couch and sits down.
Kind of boring right? It's not exciting and doesn't get the audience hooked into the film. As a writer, you need something that's going to blow your audiences mind or at least catch their interest.
As I've mentioned plenty of times, it's important to get your audience hooked as early as you can prior to the inciting incident, and that starts with introducing them to the protagonist. Who are they? What are their traits? Why should we care about them?
Going back to the example previously mentioned, we don't know much about Greg and to be honest, it doesn't really drive the plot forward from the start. Perhaps the following is a better example.
INT. PENTHOUSE - NIGHT
GREG, 40s, bushy white hair, wearing a luxurious suit, storms into the room and SLAMS the door. He throws his jacket to the side, marches into the kitchen, and pours himself a glass of gin. He furiously chugs his drink, SLAMMING the glass onto the counter.
In the above example, which is somewhat improved, we kind of get an idea of who Greg is as a character. Based on the action, we can tell he's had a rough day and being incredibly hard on himself.
It's important to note that not every character needs an action packed introduction. For example, you could introduce a character by having them in a middle of a heated conversation with someone.
In Pirates of the Caribbean: Curse of the Black Pearl, when Jack Sparrow is first introduced, we see him on his sinking ship, desperately trying to stay afloat. With the musical score playing, we're automatically drawn into the story and can't wait to see what happens next.
Like I've mentioned, not every character needs a powerful introduction, but it is important that we have an idea of who they are. When you're introducing other characters, you can decide how powerful the introduction is, just as long as you're able to grab the audiences attention. If you have any questions, feel free to ask!