I have tap water for my goldfish that is VERY cloudy, so I would like to know if I can use filtered

It's in a little goldfish bowl, not in a big tank.

Chances are, if it's cloudy out of the tap, it's due to heavy amounts of limestone in the water (this is common in a lot of areas - even where I live). If it's cloudy after a couple of days in the tank, this is due to bacterial bloom (you should never change more than 50% of the water at any one time) - this is natural, and should not be cause for worry.

Do not use a clarifier for your water to clean up cloudiness - it just isn't necessary.

Do not listen to the person who told you you need to let the water set out for 24 hours. This is bull-hockey. Letting the water set out for 24 hours (if it's tap water) does not allow time for chlorine and chloramines to dissipate (that'll take well over a week).

Some filtered water is just too soft and is too pure to use in a fish tank. Tap water contains certain trace elements that are found in a fish's natural environment - most filtered water does not contain these trace elements. Filtered water also tends to be less stable when it comes to talking about pH - large swings in the pH will happen, and can cause fish death.

Your best bet is to use tap water. Use a good dechlorinator to get rid of chloramines and chlorine, as well as heavy metals. I actually use two of them with my fish. Seachem's Neutral Regulator gets rid of chlorine, breaks the chloramine bond, gets rid of ammonia, softens the water, and keeps the pH at around 7.0. I also use API's Tap Water Conditioner, which gets rid of chlorine, breaks the chloramine bond, and gets rid of heavy metals.