Welcome to the forum.
Basically you should keep the overall rolling circumference as close as possible to the existing wheels. For 16" wheels this normally means having lower profile tyres - ie less tyre sidewall height to compensate for the 1" larger wheel diameter. If you dont compensate in this way it changes the overall gearing of the car, which could make it a pig to drive, slower acceleration etc.
Changing the tyre width can also affect handling, could foul on bodywork etc. And the wheel needs to fit a honda. You need the correct wheel stud pattern, the correct size centre bore (the hole in the middle ) and a suitable Offset ,also called ET. The ET affects how the wheel sits in the wheel arch. It may be too far in, or poke out beyond the wheel arch . You need to do a bit of reasearch on this to chose suitable wheels.
Check out the following web site and put your existing wheel/tyre size in to see acceptable alternatives
https://www.willtheyfit.com/ Not sure about OZ but in the UK you normally need to inform insurers if you change wheel size,and they may charge more. 15" wheels normally have a slightly better rides on rough roads . Low profile tyres on 16" rims may be a bit more harsh, but may handle a bit better.
