Cloudy Water In The Fish Tank? I Need Help!

We welcomed in a new member of the family....Sweety Pie.  A gold fish.

 I know it's fun when my daughter wins one at the carnival...yay,  we have a fish.  And Sweety Pie is a cutie..but for some reason the water is cloudy in tank?  This happened once before when we had a fish.

Do you have fish?  How do you keep the water in your fish tank clear?  Is there anything out there for clear water?