Most visitors to Vanuatu arrive from Australia, and the question people ask is whether to sort connectivity before leaving or on arrival. Sort it before. Your Australian plan will either not work in Vanuatu at all or will charge international roaming rates that make a few days of maps and messaging cost more than the flight's checked bag.
Install the eSIM at home while you still have wifi, leave it switched off, then turn the line on when you land at Bauerfield. Your Australian number stays active for calls and texts on your normal SIM, and the eSIM carries the data.