The next things you need to get urgently is a quality liquid test kit like an API Master kit, and a quality dechlorinator (we all recommend Seachem Prime). Prime will temporarily neutralize ammonia and nitrIte for 24-36 hours to buy you time between the daily water changes you're going to be doing.
Goldfish are not something I have much knowledge about, but the rule I've always heard is the first goldfish needs 20 gallons, and every other goldfish needs an additional 10 gallons. So for 8 goldfish, you'd need a 90 gallon tank. You're going to have to rehome some (hopefully all) of them. Goldfish are much dirtier than other fish and put out a LOT more waste than other aquarium fish.
The ich is a whole other issue. It's a parasite that can quickly take over a tank and medicine doesn't usually cure the cause. Here's a link about dealing with ich-
http://www.aquariumadvice.com/articles/articles/29/1/Freshwater-Ich-Yuck-/Page1.html
Some ich meds can also destroy your bio-filter, but since your tank is uncycled, that really isn't the issue here.
There's other things I can mention, but the bottom line is that the fish need to be returned or rehomed. I'd go back to Petsmart and yell at a manager and tell them the sales rep sold you all those fish without explaining their needs, and into an uncycled tank. Also the fact the fish got ich is a very poor reflection of the store...unfortunately very common for chain stores though.
I'm sorry I don't have an exact remedy for you, but TBH this is a bad situation where you have to remove the fish from the equation.
We'll all help the best we can, but for now, follow the cycling guide I linked before, try to rehome the fish, buy a test kit and big bottle of Prime, and hopefully start all over with the knowledge you've gained :-(