WASHINGTON — At the end of his first day as president, after the ceremony and speech, the parade and all the balls, Barack Obama found himself home in the White House and unsure exactly where to go. "It's a pretty big house," an aide said.

A pretty big job, too, he might have added.

Days into his presidency, Obama is starting to find his way around the halls not only of his house but also of power, making the transition from campaigning to governing and taking his first steps to mold the office into what he wants it to be.

From his transition to the tone of his inaugural address to his first orders and meetings, Obama signaled that he wants to change the country's course as he promised in his campaign, but that he'll move cautiously at times, work to build consensus rather than adopt a my-way-or-the-highway style and reach out to the right, not only symbolically but also substantively.

"Their focus is on sending an image of efficiency and centrism, and an attempt to move from the soaring rhetoric of the campaign to the nuts and bolts of governing," said Dennis Goldford, a political scientist at Drake University in Iowa.

SOBER ADDRESS

Obama set the tone with an inaugural address that was sober about the challenges facing the country as well as uplifting about the nation's prospects.

"The challenges we face are real," he said. "They are serious and they are many. They will not be met easily or in a short span of time. But know this, America: They will be met."

He also used the speech to suggest sharp breaks from the Bush years: a turn away from a laissez-faire approach to the marketplace, a return to greater cooperation with allies, an opening to rogue nations. He also opened the door wide to a post-partisan way of doing business in Washington.

Some of his first actions underscored a cautious approach that's natural for the law school professor in him.

With a flourish, for example, he signed an executive order to close the detention facility for suspected terrorists at the U.S. naval base at Guantanamo Bay, Cuba. That was a campaign promise enormously popular with liberals.

Yet he gave the Pentagon a year to figure out what to do with the people detained there, including deciding how or whether to try them in civilian or military courts.

"I was struck by the caution implicit in what he said about Guantanamo, that he expressed a certain amount of surprise at just how dangerous these people are and that this won't be the easiest thing," said Michael Franc, the vice president for government relations at the Heritage Foundation, a conservative research center.

"He's making the transition from being a candidate to being a leader. Sometimes when you start getting the intelligence briefings, it changes the way you look at the world."

Obama has moved carefully as well on another issue that's inflamed the liberal base of his party: the pressure to prosecute Bush administration officials on war crimes charges. Obama has signaled that while he'd be open to the idea of a prosecution for a flagrant violation, he's not interested in political retribution.

SYMBOLIC GESTURES

He's also made symbolic gestures that reach beyond his liberal base.

At his inaugural, he invited Rick Warren, an evangelical pastor who opposes gay marriage, to give the opening prayer.

On Thursday, he opted to wait a day before he signed an order lifting a ban on taxpayer-financed abortion counseling. Signing it Thursday — the same date that President Bill Clinton signed it in 1993 — would have been more of a slap in the face to anti-abortion demonstrators who were in Washington that day on the anniversary of the Roe v. Wade decision legalizing abortion. He signed it Friday.

SENATE APPOINTMENT

Also on Friday, he jumped into a brouhaha over the appointment of Rep. Kirsten Gillibrand, D-N.Y., to fill the Senate seat vacated by Secretary of State Hillary Clinton.

Some liberals complained that Gillibrand is an opponent of gun control who's backed by the National Rifle Association, and New York Democrats hinted at a primary fight in 2010.

Obama vouched for her, however, praising her as a "wonderful choice" with the "integrity, character and dedication to public service to help us achieve our greatest goals."

Ultimately, the first test of Obama's leadership style will come over his proposal to spend $825 billion to stimulate the economy. He reached out anew to Republicans on Friday, inviting top Republican lawmakers as well as Democrats to the White House.

"The administration strikes me as open to our suggestions," Sen. Mitch McConnell, R-Ky., the Republican Senate leader, said after the meeting.

While Republicans push for more tax cuts and less spending, McConnell said that he found a president who was still willing to talk, perhaps more than congressional Democrats.

"The American people overwhelmingly voted for the approach offered by Democrats," House Majority Whip James Clyburn, D-S.C., said in an interview with McClatchy Newspapers and Washington Post reporters to run today on C-SPAN's "Newsmakers."

That may be Obama's great challenge as he heads into his presidency: finding a way to bend his party a little more toward the center, and the other party leftward to meet them.