The Reagan White House today reaffirmed its support of the Federal Reserve's tight money policies as the president began winding up his month-long California vacation in preparation for a return to Washington later this week.

Reagan spent a quiet day in his suite at the Century Plaza hotel here, meeting in the morning with Wilson Riles, California superintendent of public instruction, who presented to the president a proposal to involve private enterprise in fighting youth unemployment.

Later in the day, the president was presented with a pair of cowboy boots by singer Rex Allen and Tony Lama, an El Paso, Tex., bootmaker.

The White House had no official reaction to today's drop in the prime rate, but White House spokesman Larry Speakes, in response to questions, said the Federal Reserve's tight money policies, which have been blamed for high interest rates, are compatible with the administration's anti-inflation program.

"Generally, we have been in tandem with the Fed," Speakes said. Later, he added, "High interest rates are not the policy of this administration."

Speakes' comments came in the wake of statements Sunday by Federal Reserve chairman Paul Volcker promising a continuation of stringent money policies.

Speakes said he would not attempt to predict whether today's decline in the prime rate was the beginning of the decline in interest rates expected by the White House, but he said administration officials remained confident that rates would drop by the end of the year.

The White House spokesman also dismissed a report in Newsweek magazine that the president worked "two to three hours" a day and preferred telling stories about his acting days to immersing himself in details of his administration's policies.

"The president's record in his first six months in office is an elegant refutation of the article," Speakes said.

Reagan's meeting with schools superintendent Riles lasted about 40 minutes. Riles and the president have known one another since 1970, when Reagan was elected to his second term as California governor and Riles was elected to his current post.

The black educator said Reagan appeared receptive to the plan for a private-sector fight against youth unemployment. Riles, who asked for the meeting, said he based his proposal on the model of California companies, including Rockwell International, who he said have successfully trained young people from inner cities and helped them find jobs.

Reagan returned to Los Angeles Sunday from his ranch in Santa Barbara for two more days of relaxation before leaving Wednesday for Chicago. There he will attend a fund-raiser Wednesday night and speak before the United Brotherhood of Carpenters and Joiners on Thursday.

It will be Reagan's first appearance before a labor audience since he fired the striking air traffic controllers a month ago. The invitation to speak to the carpenters union was accepted before the traffic controllers went out on strike, but White House officials said they have no apprehensions about Reagan appearing before the union group.

Reagan will return to Washington Thursday afternoon.