t* * *DICK CLARK says he manages (at 37) to keep himself youth-oriented “by talking to kids, which most adults don’t’* . . . Fan magazine editor Dick Hell-1 er (who just had his first child after W/2 years of marriage) has a book for television fans—a paperback called “Who’s Who in TV” . . . Clint Walker taking a course in boxing technique from ex-champ Archie Moore before he does “Requiem for a Heavyweight” in San Diego’s Circle Arts Theater . . . Petula Clark doing a one-woman show for French television . . . Hugh O’Brian is doing “Cactus Flower” on tour, with Elizabeth Allen, mainly in the hopes of snagging the lead in the movie version.