Yes they are both correct. The first one makes more sense to me, because it talks about the general availability of a home cooked meal. The second is okay also, but a little less logical, because I know that I can't get it a store, so I wouldn't be looking there in the first place. But both can work in certain contexts. I like the first one better. But that's probably just my preference.

Yes both are good. The first suggests that the store/shop may not sell the item. The second that maybe the shop sells it but you can't find it, you may have been better saying you won't find it at the store, but it's a small point.