The nation's governors gave strong support today to President Carter's welfare reform plan, but scored some of his approaches to the energy problem and crime control.

The opening session of the annual governor's conference saw little attention paid to the prime Washington topics of the Panama Canal treaties and the problems of budget director Bert Lance.

But Democratic National Chairman Kenneth M. Curtis, a Carter ally, told reporters after a closed-door breakfast of Democratic governors that things like the Lance affair "don't do you any good . . . the longer it goes on, the more negative it gets." But Curtis also echoed the White House assertion that Lance deserves "a chance to tell his story" to a Senate committee before facing a decision on resignation.

Illinois Gov. James R. Thompson, a leading 1980 Republican presidential hopeful, told reporters that Lance should reign but said he did not think the incident so far was causing Carter any "serious political damage."

"The President and Mr. Lance both know what has to be done and they should do it," Thompson said. "He has lost his usefulness as director of the budget. He has a right to answer the charges, but once he's testified, he should resign."

Joseph A. Califano Jr., the Secretary of Health Education and Welfare, launched the two-day meeting with a fervent plea for help from the governors in passing the Carter welfare-reform plan.

Citing what he called strong newspaper editorial and public support, Califano said that "if we do not let disagreement about program details lead to an impasse," there is a histroic opportunity to reform a welfare system that he said has kept both recipients and taxpayers "twisting in the wind."

New York Gov. Hugh L. Carey, the head of the governors' committee on welfare, responded that the state executives would "come out like tigers and lions and cougars, fighting for this type of program."

In the subsequent discussion some small-state governors raised questions about the sizeable relief that would go to New York and California, but most seemed satisfied with Califano's pledge that evey state would save at least 10 per cent of its present welfare bill if the Carter proposal is passed. A formal resolution supporting the principles of the Carter plan is expected to be adopted Friday.

There was considerably, more controversy about Carter's approach to the energy problem, and at their breakfast today. Democratic governors took out some of their frustration on Jack H. Watson Jr., the assistant to the President for intergovernmental relations.

The general criticism has been that the President ignored or minimized production incentives while concentrating on energy conservation measures. When that criticism was raised at a meeting of governors Carter called in Washington last summer, he responded by promising to meet with them again for another session focused on production incentives.

Two weeks ago, Kentucky Gov. Julian Carroll (D) wrote Watson to urge that the "production conference" be held soon so that its recommendations could be conveyed to the Senate, which is now considering the energy legislation.

Watson told the governors today that the conference was planned for the last half of November, after the scheduled congressional adjournment, and the news was not well received. Governors from energy-consumer states joined the producer-state executives in the criticism.

Watson said later, however, that it "takes time and planning" for a successful conference, and Secretary is too busy "setting up his department and dealing with Congress" to have such a meeting soon.

In an afternoon panel, Deputy Attorney General Peter Flaherty ran into stiff criticism of a Justice Department task force report proposing major changes in the Law Enforcement Assistance Administration. Several governors, including Virginia's Mills E. Godwin Jr. (R), criticized the closing of LEAA regional offices and a proposal to bypass the states and give some LEAA funds directly to cities.

In other session, Secretary of Commerce Juanita Kerps warned that the emerging debate between "sunbelt" and "frosbite" states "threatens to be divisive and polrizing" to national interests.