ONE OF THE DIFFICULTIES with being a poet is that you generally have to be something else, as well, in order to pay the mortgage. And, outside of such spots as Bread Loaf, New York's 92nd Street "Y" and anywhere readings take place, if you tell people you're a poet, they'll either look blank or expect you to start spouting "Trees." Moreover, poetry sales are not one of the economic mainstays of publishing, and most booksellers greet first volumes of poems, if not all volumes of poems, with torpor. Amy Clampitt, a poet whose first book, The Kingfisher (Knopf) is just out to such almost unheard- of acclaim as a four-page, thoughtful rave from Helen Vendler in The New York Review of Books, knows these facts of life firsthand.

"I've been writing poetry since high school off and on . . . mostly on. I thought I was a novelist but I wasn't. I guess I decided I was a poet in 1966 when I sat down and wrote a long poem of about 200 lines." But she couldn't get anything into print. "Then, in 1972 sometime, I met a printer who had a letterpress. I took him a few poems and we did a nice little book, 500 copies. That was fun." What happened then? "I sold about 5 of them and gave the rest away." During this time, Clampitt, who explains in the course of a telephone interview that she isn't a young person (though she says she feels closer to those in generations beneath hers), worked "in and around publishing, doing research, compiling indexes and editing a lot of manuscripts." She was even for a time a reference librarian for the Audubon Society and calls that one of the reasons an interest in the natural world informs her work.

Baron Wormser, a 35-year-old Baltimore native transplanted to Maine for the past 12 years, is still a librarian. Publishers Weekly called his first collection of poems, The White Words (Houghton Mifflin), "a remarkable book that demands our attention; it may even be a great one." Wormser, too, thought he was a novelist in the beginning, although he says he's been interested in poetry almost his entire life. "I didn't go to writers' school or anything like that, but I read poetry on almost a daily basis." Interestingly, Alice Quinn, who is Clampitt's editor at Knopf, gave Wormser his first break. She recommended him to John Nims at Poetry magazine who wound up featuring Wormser in one of their special "first appearances" issues. That was in 1981.

Comments Quinn, who's been editing at Knopf for nine years, "Baron's career turned around so quickly." However, because the upcoming poetry spaces on her list were already committed, she had to watch Houghton Mifflin's Tom Hart claim Wormser. For these editors, since it can't be money, it must be Art that motivates their vying for the sponsorship of new poets. (Although the first books of two of Quinn's poets last year, Brad Leithauser and Katha Pollitt, were successful enough to require second printings, still that means only a total of, say, 4,000 copies apiece.) Yet, since Clampitt eventually found herself being published in magazines large and small (starting with The New Yorker in 1978)--as did Wormser--you don't pull these budding Lowells and Bishops out of a hat, so to speak. The people who follow poetry are waiting to see what an assembled body of work looks like. Quinn agrees, "It makes a big difference to read a whole."

Wormser and Clampitt have things in common besides library science and previous obscurity. To name one, they admire each other (and have exchanged letters saying so). For another, notes Alice Quinn, neither of them "knows that many other writers." Nor are they attempting any longer to write prose. Says Wormser of the novel he once wrote and which won him admiring rejection letters, "I've changed so much the way I write, I don't have much interest." Perhaps neither will become household names, and it's unlikely that riches will follow the good reviews. However, what will happen is that demands for them to read their work around the country will increase (though Wormser will be hard to make arrangements with, since he has no phone), and there will probably be teaching fellowships offered, guest lectureships and the like.

So, a poet's life, once recognition comes, is just busier than before, and many complain that it suddenly becomes hard to find the time to write. But both Clampitt and Wormser have been thinking of themselves as poets without worrying whether anyone else did. Now that they've ''arrived," in poetry circles anyway, these are their last moments of what Alice Quinn describes as "pre-celebrity." That should be okay with Clampitt, for one, who admits, "there's a secret ham in me." CAPTION: Picture 1, Baron Wormser, Copyright (c) 1983, by Sandy Agrafiotis; Picture 2, Amy Clampitt, Copyright (c) 1983, By Henry Cox