The campaign staff is lined up, the office is ready, the contributors seem willing, and George S. McGovern is on the verge of committing himself formally to become a candidate for the 1984 Democratic presidential nomination.

"I'm resolved in my own mind, and this is what I've tried to explain to my family and my key people, that whether we win or not it would be worth doing," the former senator and 1972 Democratic nominee said in an interview here last week.

"Whether I'm nominated or not, I think that I could focus the attention on issues in a way that might sharpen the differences with Reagan," he said.

McGovern said he will announce his decision within two weeks. He said the odds were strong that he would become the seventh Democrat in the race.

McGovern, who came from far behind in 1972 to defeat a dozen rivals for the Democratic nomination only to lose by a landslide to President Nixon, agreed that he again would be a long-shot candidate. But, he added, "I'm going into it with the hope that lightning will strike."

McGovern said he had lined up a half-dozen experienced campaign staffers to form the heart of his team, and all are ready to go. He said he also had a commitment from a veteran financial manager and that initial contacts with potential contributors had convinced him he can raise $100,000 within two weeks of an announcement.

"That'll qualify me for $100,000 in federal matching, and I think we'll go well beyond that," he said.

One reason for hesitation, the soft-spoken native of South Dakota said, is "the fear of ridicule . . . the fear of just looking like a Don Quixote and a kind of, you know, 'Jesus! Not George again!' "

That concern, McGovern said, is overridden by two other considerations. First, he said, "I'd like to be president."

But McGovern made it clear that he also is drawn to the bully pulpit a presidential campaign provides. "At my stage in life," McGovern said, "the best place right now for me to be heard is in that presidential forum."

McGovern, 61, gives dozens of lectures from coast to coast each year. "But as a non-officeholder and not running for anything, it doesn't command network attention," he said.

"I've been really hitting hard at the Reagan policies in the lectures , and then I walk down the street here on Connecticut Avenue and people say, 'I never hear anything about you anymore. Don't you feel like speaking?' "

McGovern, defeated in his reelection bid in 1980 by Republican James Abdnor, spoke forcefully about his desire to address a national audience about the "rigid and hard-line and interventionist . . . foreign policy" and the "uncontrolled budget deficits" that he describes as the chief results of President Reagan's White House tenure. He wants to remind audiences of the "old-fashioned Democrat's commitment to full employment."

He said he wants to warn Americans about the "real danger" that U.S. soldiers will be sent to war in Central America. The present peril in Central America has resulted partly from "dumb things we've done for the last 20 years," he said. U.S. policies have forced Cuban President Fidel Castro to become dependent on the Soviet Union, in the view of McGovern, who added, "Don't blame Reagan for this. The Democrats are just about as bad."

American "isolation" of Cuba, McGovern said, stems from each new president deciding that he has to be tough on some communist country. "We don't dare not to have some kind of working relationship with Russia . . . so why not kick the Cubans . . . . It's a little dinky country anyway, and it makes us look tough."

McGovern, who has met with Castro in Cuba, said, "I think you can deal with him." He said the United States could persuade Castro to withdraw Cuban military forces from Central America and reduce tensions there.

McGovern said that, if he decided to run, he would set forth programs to reduce the federal deficit. These would include large reductions in military spending and efforts to increase federal taxes imposed on businesses and well-to-do individuals.

He also would endeavor to increase federal spending on employment programs and would undertake a large-scale public works program to rebuild deteriorating highways and public structures.

McGovern and his family talked about a possible presidential race last month at a vacation retreat in the Smoky Mountains. He said his wife, Eleanor, and three of his five children were "worried about the . . . strain." But he added, "They're going to go along. They're going to go along."