There is no one right way or wrong way to set up an altar. Go with what feels right for you. This particular set-up is based on the premise of the altar being split into two halves with one half representing the Goddess and the other representing the God. Most practitioners have the left or western side representing the Goddess but we know others who have the eastern side representing Her. Either is fine.
Traditionally the Goddess candle is white or silver and the candle for the God yellow or gold. The items listed for each half are not sacrosanct. You can put as much (or as little) as you like on an altar. Very often this will depend on the space you have available as altar sizes vary so dramatically.