CLIFTON - Radio and television performer Jean Shepherd is bringing his one-man show to the auditorium of Clifton High School May 15 as a contribution to Youth Week by teen-age members of Creative Images Council. He will give a two-hour performance, which is not unlike his nightly radio show over WOR, but has the advantage of visual emphasis as his rubbery face and expressive hands combine to depict some of the persons or things he talks about. His presentation is a popular one on high school and college campuses, though such I appearances have become fewer in number recently since he started producing and hosting "Jean Shepherd's America" over the Public Broadcasting System, represented by Channel 13 in the New York area. Besides his broadcast roles, Shepherd writes a regular column for Car and Driver and is a contributing editor of Playboy, and is the only writer to win the latter magazine's humor-satire award more than once - four times, in fact. He authored a successful novel, "In God We Trust, All 0thers Cash," wrote the screenplay for the Academy Award-winning film ''Summer Incident, and has appeared in a number of Broadway and off-Broadway plays. His program at the high school will begin at 8:15 p.m. Tickets may be purchased in advance at Creative Images Council, 1414 _Main Ave.; the Botany Village office, 261 Parker Ave., or from Key Club members at the high school. With the gleeful connivance of his radio listeners Shepherd pulled one of the most successful literary hoaxes in the nation in the early 1960's when he openly fabricated the identity of an author on his program, chose a title and a plot for his mythical writer to have written, and asked listeners to ask for the non-existent book in bookstores. In a few months a considerable demand was created for the title, "I, Libertine", and gossip columnists referred to it and the mythical author as real. The publishing industry was mildly embarrassed when no one could trace the source of the book. When the hoax, which was fashioned and shared publicly by hundreds of thousands of Shepherd listeners, was eventually revealed, he wrote the book and it was published, the proceeds going to charity.