Do you need more than one plant of eggplant or zucchini for it to pollinate? I bought only one plant of each.
Both eggplant and zucchini have everything they need to set fruit on each individual plant. The eggplant has the male and female parts on the same flower, while the zucchini has separate male and female flowers. You can identify the female flower by the very small fruit behind the flower.
The only other thing necessary is a pollinator; bees.