Views can be browsed through the object browser in the bottom left corner of the screen with a storyboard open. Views consist of sub classes of the UIView class, each tailored to specialized tasks.
Examples of common views:
Drag and drop combinations of these onto view controllers to build App interfaces.
Customize views using the pane on the right side in InterfaceBuilder. This changes properties on the views, which can also be done programatically.
For example, labels, textviews, and textfields have a property called text, a string holding the text contents of the view. Change this property in code to change the text of the view. Google to discover other needed properties.
Note that any interaction with views happens inside of controllers, and as such the controller needs a reference to the view. Provide this reference through IBOutlets.