President Reagan agrees with Senate Majority Leader Howard H. Baker Jr. that Congress should defer action until next year on the controversial "social issues" like abortion and school prayer so those battles won't complicate passage of his economic recovery program.

The president's position, discussed in a wide-ranging interview with The Washington Post, is likely to upset some of his New Right conservative supporters who bridled last week when Baker announced that Senate Republicans have agreed to postpone action on the so-called "social issues". Several leading conservative senators promptly insisted there is no such agreement.

Reagan, when asked about Baker's strategy for postponement, replied:

"I can't quarrel with that. Right now, we're concentrating on this package, and I don't think Congress in my memory has ever been faced with anything in quite the dimensions of this.

"This doesn't mean that we've drawn back from our position on many of thes social goals. It just means that these are things that we think must wait while we dispose of this problem and, once we get that out of the way and get economic recovery under way, then we can discuss priorities with these other measures."

Beyond that question, the president offered a generally sunny review of his political prospects after two months in office. He is pleased with the fast pace of his economic reforms and the widespread public support.

He dismisses the considerable public opposition to to his initiatives in El Salvador as "confused" and even suggests that domestic political critics are under the influence of a "well-orchestrated" communist propaganda campaign launched by Cuba and the Soviet Union. U.S. involvement

Is there any danger, Reagan was asked, that opposition to in El Salvador may spill over and weaken public support for the Reagan economic program?

"No, I don't think so," the president replied. "But I do think that we have to recognize that the campaign against what we're doing, the helping of El Salvador, is a pretty concerted and well-orchestrated thing, propaganda that I think has confused a great many people and many well-meaning people."

When he was asked to explain further, the president noted that the same slogans and placards against American involvement in El Salvador have turned up among protesters in Europe, Canada and the United States.

"Well, it's even been worldwide," he said, "and you find the same slogans being used in demonstrations in European countries about the United States in El Salvador. You find it here. There were some of those demonstrators in Canada on our recent trip . . . The placards were the same. dThe slogans were the same there."

Since it is established, he said, that the Soviets and Cubans are supporting the guerrilla fighters in El Salvador, "you have to assume that they must also have a hand then in the propaganda."

The 40 minute interview in the Oval Office began with a question inviting the president to summarize his feelings about his new job. Reagan, responded with statistics. He ticked off numbers about his 66 days in office and all that had been accomplished -- actually, only 48 days, he noted, if you go by a five-day work week.

In that time, he said, he has met with 400 members of Congress; held 14 Cabinet meetings; met 10 times with governors, mayors and state legislators; conducted diplomatic sessions with "about seven heads of state and six foreign ministers," and visited one country, Canada.

"No, there haven't been too many surprises, but I've, frankly, I've enjoyed grappling with the problems that heretofore I've just talked about," Reagan said."

"I think I was very much prepared for the confining nature of the job and how all-absorbing it is," Reagan observed. "You know, that I wouldn't be able to go home and pick up a novel and read for pleasure. I'd go home and read more of what I'd been reading here at my desk in the evening."

While he is generally pleased and proud with the opening weeks of his tenure, the president criticized himself for one small gaffe -- blaming the tenure, the president criticized himself for one small gaffe -- blaming the press for blowing up the controversy between Secretary of State Alexasnder M. Haig Jr. and the White House over control of government actions in times of crisis.

At the height of the Haig crisis last week amid reports the secretary of state was contemplating resigning, the president had told reporters that his reaction to the beginning of the controversy was "that maybe some of you were trying to make the news instead of reporting it."

"I shouldn't have said that," Reagan said with a laugh during The Post interview. "I thought I was trowing off a funny the way the question was asked and it didn't turn out that way and I probably shouldn't have said it."

Is Haig is on board to stay after the dispute in which he unsuccessfully challenged the decision to give crisis control management to Vice President Bush? The president replied:

"Certainly as far as I'm concerned. And I think as far as he's concerned, yes."

Reagan talked about the flap as one might discuss a family squabble. "As far as I'm concerned there, everything's been resolved peacefully and we're all very happy," Reagan said.

His main accomplishment, the president said, has been the economic program which he called "the greatest attempt of savings in the history of the nation."

Just as he dismissed domestic opposition to his El Savador policy, Reagan appeared equally confident that his problems with blacks could be overcome if they better understood his programs.

Blacks "have jumped to false conclusions" and have the incorrect impression that they are going to suffer more than others from his budget cuts, Reagan said.

"And I just think that they have been misinformed and in some instances by their own leaders," he added.

"They actually, because they do have a higher rate of unemployment than the majority, have a higher proportion of the people in the lower-income groups," Reagan said. "They're going to be the first to benefit with the elimination of inflation, with the creation of jobs and productivity, reducing of unemployment."

Among opther subjects, Reagan discussed drug abuse and said the federal budget reductions of drug-abuse programs are aimed only at "things we don't think have proven effective," but he and his wife continue to feel strongly about attacking the problem.

"If we're going to get a handle on this problem, it's got to come from converting the users," he said. "We have to take away from the drug trade their customers with a program that educates particularly our young people, not to follow that path, and I beieve that's possible. And do-able."