naive

Synonyms: aboveboard artless callow candid confiding countrified credulous forthright frank fresh green guileless gullible harmless ignorant impulsive ingenuous innocent innocuous instinctive jejune lamb like a babe in the woods natural open original patsy plain simple simple-minded sincere spontaneous square sucker unaffected unjaded unpretentious unschooled unsophisticated unsuspecting unsuspicious untaught unworldly virgin wide-eyed

Antonyms: experienced leery skeptical wise