President Carter called yesterday for the Democratic Party "to heal existing wounds" from the long primary contest between him and Sen. Edward M. Kennedy, but he also took a swipe at his opponents for making "false promises" and "distortions of the issues."

Making his first appearance at his national campaign headquarters here, during which he all but claimed to have locked up the nomination, the president reiterated his rejection of Kennedy's demand for a debate.

Asserting that "the issues have been thoroughly debated," Carter said that the August Democratic National Convention in New York is "a place for debate, a place for discussion," and added, "We do not fear the Democratic convention."

Without mentioning Kennedy or others by name, the president chastised his opponents while discussing what he called the "disadvantages" of incumbency.

"An incumbent president of this great country cannot deal in empty slogans, cannot deal in words, cannot deal in false promises, cannot deal in distortions of issues," he said. "An incumbent can't yield to the particular pressure of a regional or a local interest group. An incumbent has to deal with what's best for all the people every day."

Carter followed these remarks, which appeared to be directed at Kennedy, with his call for party unity.

"It's incumbent on you and me to heal existing wounds, not to create new wounds in our party," he said. "It's time for us to pull the different elements of our party back together, to be generous in victory, to be strong looking to the future, to be confident, to be united, to be determined and not to fail. I do not intend to lose this election in 1980."

The president also told the more than 200 campaign workers gathered to hear him that he wants "a strong series of victories" in the final primaries between now and June 3 that will "leave us with a strong Democratic Party."