Congratulations!
It can be done, it is easiest when the duck is female. Drakes can hurt chickens in they try to mate.
Ducks have a different relationship with water than chickens do. You might be best off having the chickens' waterer up a little higher to discourage the duck from using it, and be sure to have a nice deep bucket for drinking, and a kiddie pool or concrete mixing pan for the duck to bathe in.
Have you looked at the stickies? We have tried to put helpful information there. Please keep asking more questions here, though, the Duck Forum has knowledgeable, friendly, and fun people.
Welcome!