Open the Padding settings by clicking on the arrow in front of it:

 

 

You can now either set the distance of the chart to the border equally for all directions or set the distance individually for bottom, left, right and top. For the Image Type you can switch between Metafile and Bitmap. The Appearance Name changes the colors of the chart (for example Default or Nature Colors).

In the chapter Text Element you will find out how to set the formatting rules.  

 

If you click on the arrow in front of Fill Style you open more settings: