Adam and Eve had 2 children caine and abel, therefore making 4 people on earth?

If caine killed abel, that left 3 people, adam, eve and caine, Now caine travelled to a village where he met his wife, Forgiveme if im wrong but where did the village come from, where did his wife come from, after all there were only 3 people on earth at this point. Did she come from the aliens or as i suspect the bible is slightly untrue and a book of contradictions and mistakes