How do I draw this?

Khan, Hi.

Here is a down and dirty way to create Torn Paper.

In your Brushes Panel, Load Artistic_Chalk, Charcoal, Pencil preset

These are Art Brushes. Select one. Apply it to a slightly rotated Line. Here I gave that line a Stroke weight of 2pt.

Expand Appearance of the Brush.

Draw a rectangle

Next Live Paint. Expand Live Paint. Delete any extra chippies if needed.

K

The way a lot of people do this would be to find a raster image and then image trace it and then cut it to the size you need.

You can also try and apply effects to a shape or line. The roughen effect comes to mind.

But also you could start with a black and white gradient and then look into the Effect > Filter gallery. Try them out, which one gives you a result you like. Afterwards Object > Expand appearance and then image trace it to get a vector shape.