I am new at QGIS and GIS in general. Basically, I have a shapefile of continents. However, I need to include further refinements. For example, within "Oceania", I need to identify New Zealand and New Guinea. How can I create a new feature that identifies "New Zeland" while it is no longer one of the polygons identified as "Oceania"?
Download shapefiles from the link at the bottom for New Zealand and Papa New Guinea. Choose the "Administrative Areas" and unzip the contents. Load into QGIS and copy the features you want into your main shapefile.