Which design pattern have to use for Object Creation?

I have multiple Object classes(like Plot,Bars, Dial Box,flight Instrument). I am creating object from object Interface class.Object Interface class has all object class creating object and returning object to client.But adding objects and changing properties of object later on tedious job. To resolve this which design pattern i have to use and how? I get to to know i have to use Factory Design pattern sub classes will decide creation of object. in my situation m not getting how to do.

client code

 void GraphView::dropEvent(QDropEvent *event)// client side code  
 {
  if (event->mimeData()->hasFormat(itemlistMimeType()))  
  {  
    if(event->mimeData()->text() == "Plot")  
    {  
        ObjInterfaceClass * pObjInterface = new ObjInterfaceClass ;// object creation  
        pObjInterface->CreateObject(CUSTOM_PLOT_NAME) ;  
        pObjInterface->DrawObject();  
    }  
  }  
 }     

Object Interface Class.h

    class ObjInterfaceClass : public QObject
    {   
          public:      
             ObjInterfaceClass(QObject *parent = nullptr);  
             static  QStringList GetObjectDetails();
             static  ObjectPropStruct LoadObjProperty(char *pObjName);
             void                CreateObject(char* pObjectName) ;
             void                DrawObject() ;
    };    

Concrete class like this concrete class so many are there

     class AlphaNumLabel : public QLabel
     {     
          Q_OBJECT
               public:
                  AlphaNumLabel(  int type, QWidget *parent = NULL );  
                  void setLabelText(int parameter);
                  void setLabelText(double parameter);
                  void setLabelText(QString parameter);   
              private:
                  QLabel *mpLabel;
                  int mLabelType;    
      };
     AlphaNumLabel::AlphaNumLabel(int type,QWidget *parent ): QLabel( parent )
     {   
           mpLabel = new QLabel(this);   
           mLabelType = type ;  
     }  

Any ideas or references are welcome