Your zucchini look fine to me. The blotchy looking leaves may just be the variety you have..nothing to worry about. Some types are that color on purpose.
I am assuming its early spring for your garden. Your plants look pretty young. Not all flowers will get pollinated, especially early in the season. The fruits will turn yellow and die if they haven't been pollinated yet. You can try planting some marigolds or white petunias nearby to attract more bees. Then be patient. Pull off the yellowed fruit and wait for more to form.
Hope this helps.