I just went into lowes and see that the dahlias there all already have growth and the bag I had bought had zero growth in it. it was seriously just a bulb and dirt, so I will be returning that and buying a new one that looks alive!

I got some dahlias last year- they come dry in the bag and I did plant mine with no apparent growth on them. They took about 2-3 weeks before I noticed thems sprouting up, and before you knew it I was staking them like crazy. My directions said to lay horizontally, which I did but like you I had some little tubers that fell off that actually did take root (that's how they propogate themselves btw).
However, you're supposed to lift them at the end of fall and store them in sand or perlite or something dry (hence the dry condition you found them in at the store) which I did NOT do, so I'm just waiting to see if they come back!

"However, you're supposed to lift them at the end of fall and store them in sand or perlite or something dry (hence the dry condition you found them in at the store) which I did NOT do, so I'm just waiting to see if they come back!"

I'm doing the same. I planted them last year and they did great but I never removed them. Hopefully they come back if not I have a plant for that pot already.