Hi Char, Welcome to OrchidBoard!
I don't think you are doing anything wrong. The buds blasted, which happens to many people's new orchids. Buds are very sensitive to changes in their environment. Just the change in conditions between the store and your home might shock the plant a little, and the buds blast. Or it didn't like the cold temperatures during traveling, depending how long it stayed in the box.
So, the point is, there is nothing you can do. Maybe 1 or 2 of the buds will survive. In any case, with good care you should see a new spike in the future.
Do you know what kind of orchid it is or have a picture? Then we can tell you how to take care of it!