Winning little revue counters disappointing Off Broadway trend; Maybe I'm Doing It Wrong Musical entertainment with music and lyrics by Randy Newman. Conceived and directed by Joan Micklin Silver.

''Maybe I'm Doing It Wrong'' is an agreeable little revue comprising more than 30 Randy Newman songs assembled from various sources and performed with easy assurance by four engaging, young entertainers. Conceived and directed by Joan Micklin Silver, the show has weaknesses as well as strengths. But the overall effect is winning. ''Maybe I'm Doing It Wrong,'' at the Astor Place Theater, is mostly doing it right.

The strengths begin with Mr. Newman's words and music, comfortably in the American popular tradition but with their own distinctive quality and freshness. His generally soft-ball satire occurs in numbers like ''Political Science,'' ''It's Money I Love,'' ''Jolly Coppers on Parade,'' and ''Mr. President (Have Pity on the Working Man).'' The refrain goes: ''I know it may sound funny, but people everywhere are running out of money.''

Among the pleasures of the occasion are Mark Linn-Baker's miming and singing of ''Simon Smith and his Amazing Dancing Bear'' and several solo turns by prettily comic Deborah Rush. Perky Patti Perkins performs ''I Think It's Going to Rain Today'' with appropriate feeling. And the versatile Larry Riley sings ''Marie'' like a love song should be sung. The quartet does nicely with the waltzing comedy of ''The Debutante's Ball,'' the blithe moral warning of ''Short People,'' and the delicate nostalgia of ''Dayton, Ohio 1903.''

The offbeat casualness of Mrs. Silver's staging and Eric Elice's choreography is ideally suited to the nature of the material. Four musicians (piano, reeds, trombone, and violin) under Michael S. Roth accompany the cast from an upstage bandstand, emerging onstage from time to time and given their own turn with ''Theme from Ragtime'' (Mr. Newman's Oscar-nominated score).

The recreational manner and holiday style of ''Maybe I'm Doing It Wrong'' are visualized in Heidi Landsman's setting - a green pocket park with a planting of red-and-white geraniums under patriotic bunting, blue sky, and fleecy clouds. The production was costumed by Hilary Rosenfeld and lighted by Fred Buchholz.

In general, disappointments have outnumbered delights around the Off Broadway circuit. The Hudson Guild came up with Margaret Keilstrup's ''Wonderland,'' a desultory and derivative memory play about unfulfilled lives set in a rundown Nebraska hotel. On Sheraton Square, the Circle Repertory Company is wallowing in ''Snow Orchid,'' Joe Pintauro's crudely written drama about the seething family resentments confronting a once violence-prone Italian-American on his return home to Brooklyn from a mental institution. Meanwhile, in the short-lived ''Lydie Breeze,'' a murky symbolic drama about a bygone America, John Guare and director Louis Malle failed even to approach the accomplishment of ''Atlantic City,'' their Oscar-nominated film.

The plays have been, on the whole, well acted. But the results in terms of theatrical accomplishment have been meager.