On the eve of the Democratic National Committee's first policy council meeting in more than two decades, Chairman Charles T. Manatt cautioned yesterday that his party is not ready to craft a response to the Reagan economic program.

Manatt took pains to describe this weekend's Baltimore meeting of the newly formed Democratic Strategy Council session as "organizational in nature."

It won't be until "the second or third quarter of next year," he said, until the council will be ready to adopt a set of policy alternatives. "You've got to let it be in place for a while," he told reporters at a breakfast meeting.

Instead, the 60 Democratic officeholders from around the country will coordinate campaign strategies for 1982.

The meeting, first of its kind since then DNC chairman Paul Butler held a series of policy meetings in the 1950s, comes at a time when Democrats have been struggling among themselves to find a new set of ideas to replace the activist-government agenda that has dominated party thinking since the era of Franklin D. Roosevelt.

Some party leaders, such as Speaker of the House Thomas P. (Tip) O'Neill Jr. (D-Mass.) and Senate Minority Leader Robert C. Byrd (D-W.Va), have been cool to the idea of an official DNC policy council, and have been advocating this fall that, as the loyal opposition, the Democrats should simply stand back for now and give the president the time to hang himself.

O'Neill and Byrd, however, are expected to attend the inaugural session, as are such other party leaders as Sen. Edward M. Kennedy (D-Mass.), former vice president Walter F. Mondale, California Gov. Edmund G. (Jerry) Brown Jr., and Mayors Edward Koch of New York, Coleman Young of Detroit and Kevin White of Boston.

Manatt also told reporters yesterday that congressional redistricting is proceeding much better than had been expected, and that the initial fears that the Democrats would wind up losing up to 18 seats have "faded away."

Meanwhile, the search for a new Democratic agenda is being waged on other fronts.

This week the Center for Democratic Policy, a new think tank meant to serve as a moderate/liberal counterweight to the conservative American Enterprise Institute, issued the first of a series of policy papers on the economy.

It called for, among other things, the application of wage-and-price controls and the adoption of tax laws that penalize large corporations that raise price or salaries too steeply.