Regarding your volunteer zucchini, we can’t tell you with any certainty what will happen, but have fun watching and waiting. It is early yet and fruits would be small at this point. They could have cross-pollinated with an entirely different squash or pumpkin of the same species, Cucurbita pepo. They are certainly edible, though not necessarily palatable. Search ‘fruits not true to type’ on the Home and Garden Information Center website. It explains bizarre things that grow out of compost piles, too.