Resplendent in white gown and veil, the young Nicaraguan bride stopped and looked nervously at her groom. The newlyweds were on the way to their wedding reception in the Intercontinental Hotel here, but the main entrance was blocked by a tall man speaking in loud English to a clutch of American reporters.

Rep. Robert Dornan (R-Calif.), who was explaining what he saw as the evils of the Sandinista prison system, did not seem to notice when she hiked up her ruffled skirts and ducked behind him with just the slightest nudge. The groom discreetly followed, going on with life in Nicaragua while Dornan stood in the doorway still being questioned by correspondents seeking his views on the Sandinista revolution.

It was one moment in Dornan's 19 hours here that seemed to encapsulate his visit. He and eight other Republican congressmen who accompanied him readily admitted that they had little time to look deeply into the complexities of life in Nicaragua. The congressmen said they wanted to see Nicaragua for themselves as part of the heated debate on President Reagan's appeal for $100 million to renew U.S. military aid to anti-Sandinista insurgents seeking to overthrow the Sandinista government.

The congressmen, who arrived yesterday at midday in a White House jet, came with what most acknowledged was a clearly defined point of view in favor of aid to the rebels, known as contras, or counterrevolutionaries. They spent most of their time here confirming it and enunciating it, said a diplomat closely involved in the visit, then left early this morning for Washington via El Salvador.

Although congressmen used to visit here frequently, the U.S. Embassy said this trip marked the first widely noticed U.S. congressional delegation to arrive in Managua since an earlier vote on rebel aid almost a year ago. As a result, the congressmen's statements, in the context of a trip abroad in a presidential jet, seemed likely to generate more resonance here than they would have received in Washington.

"They are happy," the diplomat said. "They got what they wanted."

"We certainly got an impression that will help us in our deliberations," said Rep. Robert S. Walker (R-Pa.), adding later: "We heard of a whole string of abuses against the church. We heard of a whole string of abuses against human rights. We heard how the prisons are being used for torture."

The Sandinista government turned out Vice President Sergio Ramirez, accompanied by Deputy Foreign Minister Victor Hugo Tinoco and Saul Arana, head of the ministry's North America desk, to meet with the congressmen. Ramirez said later this proved Nicaragua's commitment to dialogue. But government officials also let it be known that they were irritated at having to become involved in what they described as a propaganda exercise designed to improve the chances of Reagan's proposal in Congress.

El Nuevo Diario, one of the two progovernment daily newspapers, said this morning:

"According to several authorized sources of information and analysis, the visit to Nicaragua by the group of Republican representatives supportive of Reagan's policy is a clear propaganda maneuver that allows them to drape themselves in the presumed internal 'moral authority' that is given by being -- if only in passing -- on the ground with the facts, so afterward they can 'justify' their decision to vote for the $100 million for the contras."

Besides the meeting with Ramirez, the visit included a stop at the opposition newspaper La Prensa; a conversation with Cardinal Miguel Obando y Bravo, the country's most prominent anti-Sandinista figure; a meeting with the antigovernment Permanent Human Rights Commission, and a dinner with anti-Sandinista political and business leaders hosted by U.S. Ambassador Harry E. Bergold Jr.

Dornan, responding to a suggestion that this schedule allowed little time to gather impressions on the six-year-old Sandinista revolution, replied: "Well, it's certainly more valuable than not coming here."

The California congressman said he took advantage of the meeting with Ramirez to urge negotiations between the Sandinista government and the U.S.-backed rebel movement. These talks, he said, could be accompanied by simultaneous negotiations between the United States and Nicaragua, as well as between the Salvadoran government and the Nicaraguan-backed Salvadoran rebel movement.

This matched a formula proposed earlier this week by President Jose Napoleon Duarte of El Salvador and Philip Habib, Reagan's new special envoy for Central America. The Sandinista leadership, which has made refusal to negotiate with the rebels a pillar of its policy, has issued no specific response besides reaffirming the refusal to meet with the insurgents.

Dornan said Ramirez had nothing in particular to say when the congressman brought up the idea yesterday afternoon.

"I don't think he wants to give an answer until he sees the vote," Dornan explained. "If the vote goes against them he has my question to think seriously about."

United Press International reported the following from Comalapa, El Salvador:

The nine Republican congressmen met privately in San Salvador for about 90 minutes with President Duarte, whose U.S.-backed government has been battling leftist rebels for more than six years.

The Americans then traveled to the airport in Comalapa, 30 miles south of the capital, for a news conference before boarding a plane for their return to Washington.