How to get store configuration data from Magento System Configuration?

$configData = Mage::getStoreConfig(
                   'sectionName/groupName/fieldName',
                   Mage::app()->getStore()
               ); 

How to create custom page in my account magento page

In your module's config file include your custom layout files using layout updates.

    
 
            
                
                    preferredlocation.xml
                
            
        
   

In your custom layout file include the below script(preferredlocation.xml).

 
  
    
        Preferred Locationpreferredlocation/editPreferred Location
    
  
    
      
         
          
              
    
 

Display my account navigation links in my account sidebar

In your custom layout file include the below script.

 
  
    
        Preferred Locationpreferredlocation/editPreferred Location