When you need to crop a shape in Illustrator, you first need to select the shape you want to crop. You can do this by either clicking on the shape with the Selection tool (or by pressing the CTRL key and clicking on the shape), or by using the Rectangle tool (or by pressing the R key).
Once you have selected the shape, you can use the Crop tool (or by pressing the C key) to crop the shape.
To crop the shape, first make sure that the Crop tool is selected. Next, you need to specify the area that you want to crop the shape into.
You can do this by clicking on the center of the crop area, or by using the cursor keys to move the crop area around the shape. When you are done cropping the shape, press the Enter key to confirm the crop.
Finally, you can save the cropped shape by clicking on the File button, and then clicking on the Save button.