You now have your focus character or characters. What comes next. These people can't exist in a vacuum. You need to show the setting of your story. Even if you are writing about the world of today, this world isn't one the reader knows though there are points of sameness. This is the word according to your focus character or characters. How does this happen.
First you must decide how your characters react to this world. Many times I've used the world of a hospital in my stories. Of course, there are the physical descriptions but using just this won't bring the reader into the world you've created. You can start with the place. City, town, rural area, All these worlds have differences. But placing the reader here takes more than just buildings, exterior and interior. How do you do this?
Using the senses. Not just the ordinary ones but engaging the focus character in the world by using all the senses is the key. What do they see, hear, touch, smell and taste. Suddenly the reader begins to see the world. But there is more.
How does your character react to this world you're creating. You must run the senses through the character's eyes, ears, fingers, mouth, nose. The reader will experience this world you have created.
No matter if the world is the one where we exist or some world in space or fantasy, bringing hwo the focus character reacts is the key to bringing the reader into your world.