The Reagan administration yesterday unveiled a job-training program designed to fill the void left by the demise of CETA, but it received no better than a lukewarm greeting from key Republicans in Congress.

"CETA was too expensive, too complicated, tried to serve too many different people" and led people "down too many blind alleys," Labor Secretary Raymond J. Donovan said in announcing the new direction in job training.

The $2.4 billion plan for fiscal 1983 differs from the Comprehensive Employment and Training Act in several ways. It would distribute block grants to states, which would then work with industry to set up private-sector training programs; under CETA, cities and other local governmental units had wide discretion in spending the money.

The administration plan is targeted primarily at a specific group--low-income people aged 16 to 25--rather than at a broad range of unemployed persons. It also eliminates stipends to low-income persons, and it provides for no public-service employment, one of the most criticized features of CETA.

The congressional resistance that surfaced yesterday centered not on the broad outlines of the plan, but rather on funding levels and on how it would be implemented.

A bill introduced last month by Sen. Dan Quayle (R-Ind.), chairman of the Senate employment and productivity subcommittee, and Sen. Edward Kennedy (D-Mass.), the ranking minority member of the full Labor and Human Resources Committee, calls for $3.9 billion for job training in fiscal 1983, 62 percent more than the administration figure.

Either level would represent a substantial drop from past federal funding for job training. During the seven years of CETA, which will end Oct. 1, federal outlays averaged roughly $7.5 billion per year.

Quayle introduced the administration bill on Tuesday, but he made clear through a spokesman yesterday that he did so only as a courtesy. The senator, who declined an invitation to attend the Donovan press conference, said that he was "not about to abandon the Quayle-Kennedy bill."

A spokeman for Sen. Orrin G. Hatch (R-Utah), chairman of the committee, who also did not show up for the press conference, said yesterday it "is foolish to assume the administration bill will whip through unscathed."

Donovan said that even with the cutbacks, more money would go into job training under the Reagan proposals than under CETA. He said only 18 percent of CETA funds went to training, with the rest allocated for administrative costs and direct payments to participants. Under the administration proposal, 75 percent of the funds would go to training.

The secretary said he was "sympathetic" to the argument that cutting off stipends for those in job training would make it difficult for the poorest of the poor to take part. But in the past, noted Labor Undersecretary Malcolm Lovell, "some of the participants came for the money and not for the training." As a result, he said, they did not take the training seriously.

The administration bill would train one million participants annually, the Quayle-Kennedy bill, two million.

A major difference in the bills centers on the division of state and local responsibilities.

Under the administration approach, the block grants would be controlled by the governor and a State Job Training Council which he would appoint and which, by law, would be dominated by business leaders.

Under the Quayle-Kennedy approach, local governments would retain more control over the funds.