Hi elijahsue,
It can be a bit tricky for NZ sellers to sell on eBay global sites like US and UK, because the shipping will be significantly more expensive. So yes, you would need to look at drop shipping - or else sell rare or collectible items that people would be willing to pay the extra shipping on.
Most NZ sellers that I'm aware of sell on TradeMe and eBay Australia.
Let us know how you go!