I gave my 6 month old carnation goodstart formula yesterday for the first time. Previously she had been only breast fed. She cried for 4 hours from gas in the night. Should I change formula or is this normal when adjusting to any formula? If I should change what do you suggest I change to?

Even an infant can have lactose intolerance.
I would try different brands and keep a notebook of what you gave, when, how much, and what the result was.
Be sure not to water down, and of course continue to breast feed.
Enfamil makes many varieties. There are many soy formulas that contain no cow's milk for those with lactose intolerance.
Google infant formula - many provide coupons too, so you don't go broke trying different ones.