From the Stores (Admin Control Panel -> Stores -> Settings) menu:
If checked, enables the stores module.
Important: Only products can be listed in stores. If the listing of products is disabled, stores will be disabled as well.
Complete the following fields to create a unique brand identity and establish a strong online presence:
Select the most distinctive feature of the business.
Describe in a concise paragraph why this store is different from the others.
Select the visual identity of the store.
Select the most relevant category where it would fit.
Add keywords that best describe the store to be better indexed by search engines (no more than 155 characters).
Select the categories that best describe the store.
Note: Leave empty to use the site's default categories.
From the Store Pages menu complete:
Provide a detailed description of the store to give potential customers a better understanding of the business.
List shipping methods, return policies, pick-up hours, and any other additional shipping-related policies.
Explain terms of service, privacy, refund policies, and other company-related policies
Create, in the Custom Categories menu, if there are no categories accurately describing sold products, new categories.
Important: After creating New Categories, add them to the store using the Select Categories field from the Setup menu.