Up to 12 months you can drive legally in New Zealand with your current driver’s license or an international one (an authorized translation is needed if it is not in English). After this period it needs to be converted into a NZ license. You need to have it with you all the time. Renting a car is possible if you have a full license and are 21 years or older.
In New Zealand you drive on the left-hand side of the road and drivers give way to all traffic crossing or approaching from the right.