Your plants look great, loaded with healthy leaves and flowers, but there is still no fruit. This is a common complaint from gardeners growing squash, cucumbers and other vine crops.
Start by taking a closer look at the flowers. The first set of flowers produced is all male flowers. The next set of flowers is a mix of male and female. Look for the miniature fruit at the base of the female flower. Now pollination can occur, so the fruit can develop.
Once your plants start producing, you can further increase productivity with proper harvesting. Pick bar type summer squash when it is 6 to 8 inches long. The rinds will be thin, seeds small, and flavor the best. And your plants will keep producing. Harvest cucumbers for sweet pickles when 1 ½ to 2 ½ inches, dill 3 to 4, for slicing 6 to 9 inches long and burpless or Japanese 10 to 12”.