I believe zucchini and other squash have separate male and female flowers.

The female flowers are the ones that produce the actual fruit. Your problem could be either that you don't have any female flowers yet, that the female flowers are not getting pollinated sufficiently to stimulate fruit production, or some cultural problem.

You can hand pollinate by taking the male flower and applying the pollen to the female flowers. I'm not an expert so I couldn't tell you how to distinguish btwn the two though.

The female blossom will be attached to a very small squash. The male blossom is on the end of a straight stem.
Jim