Welcome to BYC! Ducks are awesome! I have 21 adult hens and they all lay eggs regularly except for my 2 snowy mallards and 1 crested grey. Ducks are also great pets: mine let me hold them and I hand feed them all the time. My parents didn't have a problem with me getting them though, and I have a broody bantam cochin hen who is going to incubate 8-10 call duck eggs.
What ducks were you planning to get if your family let you? Call ducks might be a good idea, because of how small and cute they are.
Duck eggs are the absolute best for baking. The best cornbread, cakes, pies.... This is because they are so rich. I even scramble them up to an omelet. On the downside, they are messy. They can turn their run into a muddy pit. (Good to know all sides on an argument). And yes, you need more than one, preferably at least a hen and Drake or two hens, so it is a good idea to hatch multiple eggs. (That I'm not an expert on, we just got our little ducklings a week ago). They are super entertaining! We put our in a tub of water the other day and they went crazy! Dunking and swimming and floating it up. Even got mad when we put them back in their brooder. It was hilarious. But yes, I agree that you should find out their reasons for saying no.
Howdy Happy to have you join the family. Enjoy your time here at BYC!
I agree with @Table4Six , call ducks are small and cute and stay that way. One thing to remember is, they can take 1 drop of water and make a mudhole!but that's true for all ducks.