President Bush said on his first day in the Oval Office Saturday he is prepared to respond in kind to any acts of good will by those holding Americans hostage but will make no concessions "to free those precious lives."

"People in the past facilitated the release of our citizens, and I'd love to see that happen again, and I won't - and I won't forget it," if it does, Bush declared.In a freewheeling exchange with reporters, the new president also said he intends to meet with congressional leaders Tuesday to discuss the government's spending deficit, and has asked to address a joint session of Congress Feb. 9. Bush hinted that it would be a more specific call to action than what he termed a "thematic" inaugural address on Friday.

"Stay tuned. Feb. 9th, we'll have something a little different, if that's the date that's settled on," he said.

After a night of celebration at 11 inaugural balls, Bush and his wife, Barbara, were up early to open the doors of the White House to 4,500 ordinary Americans, many of whom had stood in line for hours in bitter cold for a special tour and a chance to stroll the South Lawn (see accompanying story).

After personally escorting 15 tourists, picked at random, through his new home, Bush took his place at the Oval Office desk occupied by Ronald Reagan for the past eight years. There, he found a personal note left behind by his mentor (see A3).

With his aging mother, Dorothy Prescott Bush, seated at his side, Bush took his first presidential news conference question:

Q: How does it feel to be president?

A: It feels just fine. It's setting in now after the glamour and excitement of the inauguration. It's a great joy to have my mother here, the leader of our family.

Later, he declared "It's the most exciting day of my life so far. It just is wonderful. Everything's been perfect. Everything's so beautiful."

Bush said, too, he would soon respond to a "generous letter" from Soviet Leader Mikhail Gorbachev (see text on a4.).

Bush's schedule included an intelligence briefing from national security adviser Brent Scowcroft and chief of staff John Sununu, an appearance at a luncheon for the financial organizers of his $25 million inaugural, and a second night of formal revelry, including a "Black Tie 'n' Boots" ball for his fellow Texans. His official inaugural calendar ends Sunday with a national prayer service at the Washington Cathedral.

Bush acknowledged he couldn't find his way around the White House his first night, after he and the first lady returned from the long round of balls. "I got lost trying to find a couple of kids' rooms, yeah," he chuckled.

Along with his mother, five of Bush's children, their spouses and 10 grandchildren shared the first night in the mansion. After a luncheon for the entire Bush clan in town - 240 relatives in all - the kin scattered.> "It's a great joy to have our kids over there (in the living quarters) last night," said Bush. "One got sick, so I had the duty at about 6 o'clock this morning - Ellie LeBlond. I pumped half a Tylenol into her and she's looking good. Ate two pancakes. What you'd call a rapid recovery."

On the hostage issue, Bush was asked if his inaugural address reflected any movement or change of policy regarding the imprisonment of Associated Press correspondent Terry Anderson and eight other Americans believed held in Lebanon by Shiite Moslems. Bush had said in the speech that "assistance can be shown here, and will be long remembered. Good will begets good will."

Bush told reporters "I don't think it's a change of policy. But I wanted to be sure I mentioned in that speech my absolute determination not to forget either . . . the POW-MIAs or these hostages. And I wanted that right in there. It was one of the few specific points in an otherwise thematic speech. And in terms of your question, I hope it was heard around the world.

"You know," Bush added, "we keep hearing rumors that countries want to have improved relations with the United States. I wanted to make clear to them that good will begets good will. I also know enough about the situation to think, in fairness, that because of the nature of the hostage-holders you can't finger any one country for holding Americans hostage against their will."