Some writers find it easy to create worlds from the ground up. They design mountains, valleys, forest, rivers and lakes. Build cities, villages and forest preserves. They populate their worlds with varieties of people. Some are like us, humanoids, while others are aliens with amazing superpowers.
Think Star Wars and Star Trek.
In both examples there are complete languages that suite the different beings. Different styles of dress. Different and unusual food choices.
These differences affect how the beings act and react. While some are peaceful, others are warlike. Some are meek, while others are aggressive. Some master yoga-like methods, while some respect and honor skills with weapons.
Your task is to design a world. Begin by drawing it. The outer borders. The seas and mountains. Inlets and ports. Think of where resources are found. Where are the farms and ranches? What types of animals and crops do they raise?
Think about the capital. What type of government and officials? How do they get in power? Are they just rulers or despots? What rules control lives?
Populate your world. Is there a mix of beings? How do they get along? With understanding or with conflict?
Do not worry about action or dialogue. At this point you are only designing.
When you are finished, look back at what you have created. What else needs to be added to the mix? What will not work and needs to be changed? What parts me you uncomfortable when you think about telling the story? Change them now, before you begin.