Wales have lost their last seven internationals since defeating Georgia in the World Cup and have not beaten the Wallabies in Australia since 1969.
Australia have a new head coach in Joe Schmidt who has taken over from Eddie Jones.
“We’ve had a good week of preparations here in Sydney and are excited to get out on field on Saturday,” said Gatland.
“This first Test is going to be a great challenge for us.
“Test matches are all about fine margins and we know we need to be accurate, keep our discipline and stay in the fight for the full 80 minutes.
“There’s a lot of talent within the Australia squad and we know they will want to come out firing and put in a performance against us this weekend.”
Wales v Australia: Liam Williams; Josh Hathaway, Owen Watkin, Mason Grady, Rio Dyer; Ben Thomas, Ellis Bevan; Gareth Thomas, Dewi Lake (capt), Archie Griffin, Christ Tshiunza, Dafydd Jenkins, Taine Plumtree, Tommy Reffell, Aaron Wainwright.
Replacements: Evan Lloyd, Kemsley Mathias, Harri O’Connor, Cory Hill, James Botham, Kieran Hardy, Sam Costelow, Nick Tompkins.