Before you can modify an object, you need to distinguish it from the objects around it. You do so by selecting the object. Once you’ve selected an object, or a part of an object, you can edit it as required.
Click the Selection tool and when the cursor changes to a pointer, click the object or an object group.
To select multiple objects, draw a marquee around the objects using the Selection tool, or Shift-click the objects.
To select objects in a group, double-click or Cmd+Click/Ctrl+Click the objects.
To select an item without a fill, click its border.
Select the object or the object group, and drag the circular handles. In object groups, you see the circular handles around the bounding box of the group. Drag these handles to resize the object or the object group.

To lock the aspect ratio of objects while resizing, click the lock icon in the Property Inspector. When you do so, the ratio between the width and height of the object is retained when you resize the object.

Select the object or the object group.
Hover over the circular handles and move the cursor slightly to the outside of the handle to see the rotation cursor (icon).
When you see the rotation cursor, drag the handle in the desired direction to rotate.
Opmerking:
In object groups, you see the circular handles around the bounding box of the group.
