Mr Birrell has been elected deputy Nationals whip under Parkes MP Mark Coulton, and he said Mr Coulton had helped show him the ropes on many parliamentary procedures and protocols.
Speaking before he was sworn in, Mr Birrell said there was a “buzz” in the building ahead of the opening.
“There’s a lot of pomp and ceremony around it ... it’s an amazing place and an amazing honour,” he said.
“I feel the responsibility of the people who’ve sent me here.”
He said it wasn’t ideal to come into parliament with the Coalition in opposition for the first time in nearly a decade, but said he was still excited to get stuck in.
“Every time the government does something which aversely affects our regions we’ll make sure we hold them to account, and any time they want to work with us we’ll work with them,” he said.
Mr Birrell has been in Canberra for the past few weeks, getting set up in parliament and the nation’s capital following his victory in the May Federal Election.
Tuesday’s opening began with a smoking ceremony and Welcome to Country and speeches from Prime Minister Anthony Albanese and Opposition leader Peter Dutton.
Mr Albanese referenced the Uluru Statement from the Heart and the record number of First Nations MPs elected in May, and encouraged MPs of all stripes to make a difference.
“I say to everyone here, all of my parliamentary colleagues, don’t miss the chance, because you’re not here for that long,” Mr Albanese said.
“None of us will be. And when you’re sitting on the porch, thinking about what you did, you can either have a source of pride, or a source of regret.”