Quo tum dolore Dido afficiebatur talia cernens! Quos gemitus dabat, cum ex summa arce prospiciens litus et mare turba hominum et navium misceri videret!
turba, -ae (f) = multitudo, multitudinis (f)
turba here is an ablative of turba, -ae (f) - the text has a macron over it.
Now it's the only ablative after prospiciens. It seems to govern (if that's the right word) the two genitives 'hominum' and 'navium'.
'...looking from the high peak she saw the beach and the sea confused (mixed up) by a crowd of men and ships.'
Am I on the right track...?