Spaceships campervans come with gas cooker / gas stoves included (2 in total: see for more info). These Gasmate (or similar quality brand) tabletop & travel gas cookers are easy to use.
They run on butane, small-ish hairspray-like gas canisters that can be purchased at many outdoor shops, department stores or camping stores around New Zealand.
How to use the gas cooker
Make sure the stove it turned off
Take the gas canister and remove the cap
Insert the gas canister into the stove. Make sure the little spray nozzle at the top is inserted correctly and that the can is aligned correctly. The space in the rim of the canister needs to be at the top so the locking mechanism can secure the canister.
Push the locking level down so the can gets locked in. If the locking lever is hard to move, make sure the space in the rim is aligned correctly.
See the video below for more info.