In Florama, there's a girl in one of the houses who will give you the TM for Pluck. Teach that to your Zubat, since it has no good moves until Level 17 or something like that.
You can train really easily when your Zubat has an actual attacking move, and Pluck will be useful for later on when Gym Leader's Pokemon hold things like Berries, and you'll take away their berry by using Pluck. Additionally, Barry will have started with a Turtwing, meaning your Zubat will be a good counter for it to cover your Empoleon.
You also need to evolve your Piplup, because this isn't the anime. :P