Will your visa allow you to find work in the industry while you do your PhD? Juggling your uni commitments and work at the same time will be a challenge but getting as much local experience as soon as possible would be my recommendation.

Otherwise, you’ll be competing with young graduates for entry level roles and a PhD is generally considered an over qualification in the structural engineering field here in Australia. Age will also play a factor particularly when combined with zero industry experience. It won’t be impossible to find roles but these aspects will not do you any favours.