The 52 former American hostages, who may return to the United States as soon as this weekend, will first be reunited with their families at a private location and then come to Washington for a public celebration of their freedom, a State Department spokesman said yesterday.

The exact shape and timing of the events of the coming week have yet to be worked out and approved by the White House, but already yesterday preliminary plans for the celebration were being laid by the District of Columbia government, Washington Cathedral, where a midweek thanksgiving service is being planned, and local hotels where hostage families will stay at government expense.

State Department officials met with D.C. police department representatives yesterday afternoon to map tentative plans for public ceremonies. The State Department was also calling for local hotels, looking for a place with 200 or so rooms that it could take over for the former hostages and their families.

State's likeliest hotel prospect yesterday seemed to be the Crystal City Marriott. General manager Paul Reinke said he has over 200 unoccupied rooms. "We are waiting any minute to have them call us and make reservations," he said.

Meanwhile, New York City officials claimed that they could do a better job welcoming the hostages back than could the nation's capital. New York Mayor Edward Koch said yesterday that the city would throw the biggest ticker-tape parade in history for the returning Americans.

"No city in the country can give such a welcome as we can," said Joe Fitzpatrick, press secretary to the New York City Council. "We are talking 3 to 6 million to turn out for this thing," he said.

But despite New York's fervor, federal authorities appeared to be balking yesterday at giving any official "host city" santion to New York.

One "ceremonial reception" in Washington will be held at Andrews Air Force Base once the former hostages have had a chance to spend at least one night privately in a secret location with their families, State Department spokesman William Dyess said in a press briefing yesterday.

Military bands and color guards representing all branches of the service will line the tarmac at Andrews to greet the hostages when their plane touches down, said a military spokesman. The ceremony is open to about 1,000 members of the public on a first-come, first-served basis. There may be other receptions in Washington, too, but Dyess said that he has not yet seen detailed plans for these.

The U.S. Senate yesterday afternoon unanimously passed a resolution declaring next Thursday, Jan. 29, a day of national thanksgiving and worship to commemorate the release of the hostages and the eight American servicemen who earlier gave their lives in an unsuccessful attempt to rescue them. The House is expected to concur soon.

Alexander M. Haig Jr., the new secretary of state, greeting his subordinates in the lobby of the Senate Department yesterday, praised the returning hostages.

"The events which we will witness very shortly here in our nation's capital -- the return of our prisoners from Iran -- will underline [that] it is the American diplomat, the Foreign Service officers of the U.S., who are at the cutting edge and are indeed the vanguard of the ramparts of the defense of American values," Haig said.

At the White House, spokesman James Brady indicated that the former hostages may not return to the United States before Monday, which would probably put any Washington celebration back to midweek.

Brady said that former president Carter, while aboard Air Force One en route home after visiting the hostages in West Germany, wrote a letter to President Reagan recommending that the hostages remain in the hospital there for three or four more days. Brady indicated the White House will go along with the recommendation.

"We don't know what kind of a time frame there will be before [the former hostages] go off to their respective homes or what they will want to do or how long they'll want to stay here," said Laura Dalley, a spokesperson for FLAG (Family Liaison Action Group), the families' umbrella organization.

Dalley said the desires of the former hostages is only one of the uncertainties. She said the uncertainity is also "partially due to the change of administrations," with the Reagan group reviewing all tentative plans for Washigton ceremonies and receptions that had previously been made by the Carter administration.

Adding to the confusion were indications yesterday from the hostages themselves that they expect to be home this weekend. Theresa Lodeski of Edwardsville, Pa., mother of former hostage Bruce W. German, said her son told her by telephone yesterday that he and other former hostages believed they would be in Washington "late Saturday or early Sunday."

Lodeski said she had not heard from the State Department about a return date and the she would call the department Saturday if she hadn't heard by then.

department spokesman Dyess said yesterday that in all the planning for repatriating the former hostages the "overriding concern" is for their health. Once it is thought by U.S. doctors examining the former hostages that all 52 are capable of coming home, they will be flown to a "private place" to spend "a day or so" with their families -- overnight certainly, perhaps as long as two nights.

There was widespread speculation yesterday about where that place would be, but it seems clear that it will not be the Washington area.

A spokesman for McGuire Air Force Base in New Jersey said yesterday that McGuire, and Dover Air Force Base in Delaware are strong possibilities for the location of the reunion. But at the same time yesterday, a spokesman for the U.S. Military Academy at West Point said that institution, with its grand old Hotel Thayer, is under consideration as the spot for the reunion.

"Should we be selected, we would be prepared," he said.

Alan Gripp, a spokesman for the D.C. government, said, "In our view it's just a little dangerous to plan too much now. It's not fair to presume to know what kind of ceremony the 52 Americans want . . . We could plan a type of elaborate thing like a parade and then what happens if they don't want it?"

A spokesperson for Washington Cathedral said yesterday that plans for an interfaith thanksgiving service are being made for next week. It is hoped that the former hostages, their families and top government officials will attend the service, the spokesperson said. A day for the service has not yet been chosen.