Does this always need the article?
Yes. In Greek, it is necessary for the article to be there.^.^
Is it Η νεολαία for male and female
η νεολαία means "youth" collectively, i.e. "the group of people who are young":
νεολαία < νέος + -λαία < λαός. Source: https://el.wiktionary.org/wiki/νεολαία