modified
unused, unaccustomed, unhabituated, unadapted, unskilled, untrained, unlicensed, untried, undeveloped, naive, unsophisticated, amateur, untutored, unschooled, unpracticed, inexpert, inefficient, fresh, unversed, ignorant, innocent, uninformed, callow, unacquainted, undisciplined, new, immature, unripe, tender, unseasoned, green, raw, verdant, youthful, beardless, chaste, virgin, wet behind the ears*, tenderfoot*, soft*; see also incompetent, young 2.
Antonyms experienced*, seasoned, hardened.