Selecting Graphics
The Selection tool is the leftmost of the drawing tools (the arrow), and it is the default tool. It's used for selecting graphics in the document and moving, copying, resizing, rotating and reshaping them.
To select a graphic, use the Selection tool and click on it with the mouse.

To add or remove a graphic from the current selection, hold the Shift key or Command Key and click on the graphic.

To select all the graphics in a region, click on the canvas and drag produce a transparent rectangle that will select anything it touches. Holding down the Option key while dragging will only select graphics that are fully enclosed by the region. Holding down the Shift key while dragging will add or remove graphics from the current selection.

To select everything in a document, choose Select All (⌘A) from the Edit menu.

Control-click (or right click) on a graphic to bring up a context menu. From there you con Select Similar Graphics or Select Connected Graphics