Item views can be created via an item type’s details view. To access it, open an item of the desired type (for example a Product item). Next to its name in the title bar is a vertical ellipsis ‘⋮’, and clicking it opens a menu where you can select “Edit type”.
In the “Views” section of the details view, click on the “Add” button and select the type of view you want to add.
In order to show something in a view, you need to define what type of items you want to see in it. This is discussed in the next chapter and also for every view separately.