President-elect Vinicio Cerezo of Guatemala, promising a newly democratic and humanitarian future for his beleaguered nation, made the diplomatic rounds here yesterday to stake out a position of "active neutrality" in Central America's festering conflicts.

Cerezo, 42, a self-described "moderate leftist," met for 20 minutes with Vice President Bush, who accepted an invitation to attend Cerezo's inaugural Jan. 14. Bush said Cerezo's election in an unexpected landslide 10 days ago was "a great inspiration to us" and offered unspecified U.S. help in Guatemala's move toward democracy.

In a long day of meetings and encounters with reporters, Cerezo declined to criticize Nicaragua's leftist Sandinista government or U.S. support for rebels fighting the Sandinistas, despite the administration's repeated statements that Guatemala backs the U.S. view.

"I prefer not to express anything about the policy of the United States" in Nicaragua, he said. "My position is to oppose confrontations."

Cerezo told a news conference that he came here to forge "a partnership in democracy" with the United States and would not ask for aid on this trip for his country's armed forces, from whom he will take office as Guatemala's first civilian president in 31 years.

"They will give us the office" of the presidency, he said. "We are going to work to recover the power." He said that if the United States were to offer immediate aid to his security forces, as provided in pending legislation, he would ask that it be delayed.

"The real challenge is not to have the best army in Central America but the best democracy," he said.

U.S. economic aid to Guatemala totaled $80.3 million in fiscal 1985.

Cerezo also met with acting Secretary of State John C. Whitehead, Treasury Secretary James A. Baker III and Assistant Secretary of State for Inter-American Affairs Elliott Abrams. He received a warm reception at the House Foreign Affairs and Senate Foreign Relations committees, where members long critical of Guatemala's record of human rights abuses said they questioned him closely on his plans.

"It was a most impressive presentation," said Sen. Edward M. Kennedy (D-Mass.). "I personally admire him and believe in his sincerity." Fourteen senators attended the meeting, and several gave Cerezo letters from constituents asking about people who have disappeared in Guatemala. Sen. Richard G. Lugar (R-Ind.), Foreign Relations Committee chairman, said Cerezo plans to ask for U.S. technical assistance in reforming Guatemala's security police force.

Rep. Michael D. Barnes (D-Md.), chairman of a Foreign Affairs panel, gave Cerezo an emotional welcome. "I have never, ever been as excited and personally honored" by any other foreign visitor, he said.

Cerezo said his "active neutrality" would mean "a more aggressive presence in the affairs of Central America," including a push for a Central American parliament as a forum for regional discussions. He said he feared that "falling into the hands of the East-West conflict" would lead to "the 'Lebanonizing' of the area, which means destruction."

Cerezo is a lifelong Christian Democrat whose years of opposition to Guatemala's right-wing military governments have meant occasional jail, exile and at least three attempts on his life. He faces a formidable array of economic and political problems during his five-year term, including a 60 percent inflation rate and unemployment that affects one-third of all Guatemalans.

His designated economic minister, Rodolfo Paiz, told reporters that neither land reform nor a widely expected tax on unused land was planned "at this time," and said Guatemala's top goal is building political stability in which the economy can flourish and popular faith in human rights observance can be restored.

The armed forces, Cerezo said, "did not put any conditions on giving me power," and have agreed to a reorganization of the secret police, the security forces and the supreme court. "I am a politician, and I feel I am a good politician in Guatemala, but I am not a magician," Cerezo said. "I request only that you give me time."