Mr Sunak said he would set out plans to “lead us to a better place” in the run-up to an expected 2024 election, having spent his first year in power “stabilising things” after inheriting economic turmoil.
Arriving in Manchester for the conference, Mr Sunak is facing Tory calls to cut taxes or tear up human rights legislation in last-ditch pre-election gambles.
In a BBC interview kicking off the conference, he said voters could expect more of the feather-ruffling style of politics that led to him rewriting Britain's net-zero policy after a backlash against low-emission traffic zones.
“What I want to do is show the country how we’re going to change things for the better in the long term and that means doing things differently,” Mr Sunak said.
The net-zero shift “is an example of it. It’s me being upfront about what’s required, saying that these are the costs that are being put on people”, he said.
“I am prepared to change things. I’m going to do things differently. I’m going to do what I believe is right.”
HS2 in doubt
Mr Sunak would not be drawn on specific policy issues such as the High Speed 2 rail link, another long-term project on which spending could be scrapped.
Manchester may never see HS2 if a second leg of the project is abandoned, despite the government's “levelling-up” agenda to address regional inequality.
Levelling Up Secretary Michael Gove did not rule out watering down HS2, saying the costs were “significantly greater than originally estimated”.
The railway is “an important project” for the levelling-up agenda but “you don't bake a cake with only one ingredient”, he said.
Mr Gove's department launched a new policy on Sunday by offering £20 million ($24.4 million) to 55 neglected towns to help them revamp their high streets.
He said the Prime Minister would use the conference to “draw a contrast between the long-term decisions that he’s taking and the approach that Labour would take in office”.
Rishi Sunak as Prime Minister – in pictures
Labour leader Keir Starmer will set out his pitch at a conference in Liverpool next week, with polls giving his party its best shot of winning since it lost power in 2010.
The date of the election is in Mr Sunak's hands but pundits expect a vote between spring and autumn next year. The latest possible polling day would be in January 2025.
Mr Sunak, who has tried to link Labour to unpopular green policies that sceptics say were never on the cards, has positioned himself as a friend of the driver against what he called a “war on motorists”.
He said he was motivated by “wanting to ease the burden on families” after a survey showed his personal wealth was prominent in voters' perception of him.
But he would not commit to pre-election tax changes, saying the “best tax cut that I can deliver for people right now is to halve inflation” – one of Mr Sunak's five pledges by which he has asked to be judged.
Another of the pledges is to “stop the boats”, referring to migrant journeys across the English Channel in primitive rafts. Mr Sunak touted a fall in the number of such crossings this year as a sign his policies were working.
A policy to deport failed asylum seekers to Rwanda has been delayed by legal appeals, leading to calls from the right of the Tory party to pull out of the European Convention on Human Rights.
Business Secretary Kemi Badenoch, seen as a potential candidate for Mr Sunak's job if he were to resign after the election, set out her stall by telling The Sunday Times that leaving the ECHR is “definitely something that needs to be on the table”.
Suella Braverman, the Home Secretary, also sparked speculation about her leadership ambitions last week with a speech saying multiculturalism in Britain “has failed”.