Use the Pen tool and create a closed path in the shape that you are wanting to create. After your shape has been created, choose Object > Content, from the menu bar at the top of your screen and select it as either:
1. Graphic & then import an image, or
2. Text to create text that follows your newly created shape or
3. Unassigned if you a want a coloured shape or an object to attach a Text Wrap.