What do you need to create your world? Ask yourself first what is your story about? What time is it? Where is it? Defining questions like these will help you create your unique world and/or recreate what we have at the moment. When you finish you will want to set up your rules for it. What can and can’t be done will help to move forward your plot.
Remember always to do research!
Time
When does this story happen? It is the 20s, 70s, now or in the future? Is it completely futuristic turning sci-fi? The time will help you with what you can/can’t do. If it is a spaghetti western, you can’t just throw a tank in it. Is it a futuristic dystopia where technology was advanced but people regressed because of a war that happens in 2020? Time will guide you on your research and how to accommodate the adversities your characters will face. Or will help you on how simple some things are because of how advanced society is.
Story Type
If you are writing fantasy, you know that world-building is a most. Audiences must expect kingdoms, warriors, dragons, and other individuals that make fantasy what it is. Is it sci-fi? Technology, spaceships, hover-boards even robots. Is it inspired by true events? Then time, place, and rules will be given.
Where
Is your setting in the Amazonian jungle? If so on the name it is given that you must do a jungle. An island? A country where there is no electricity or are living on renewable.
Asking questions on how your world moves will help you create a more knitted story. What is the religion of the place? Economy? Government? What is the opinion of society towards basic things? Is there a society? Or has humanity been wiped clean and animals are evolving?
Remember that the world you put in the story makes the base for what your characters will be interacting with. Take your time knowing where your characters will be at. What is close, what’s far? Of course, enjoy yourself. Think you are going on an adventure with your characters. Into your story. After all… you are its creator.