I have a few questions.
-are dummy cakes the Styrofoam things i see at my cake supply store?
- do i butter cream the dummy cake before i place fondant on top?
-do i need to put a dowel through the center?

any tips, help and/or advice would be appreciated

Yes, that styrofoam is the dummy cake. If it's combined with real cake and not the top layer you need to put a dowel through to stabelize all the layers. If the cake is all styrofoam or just the top layer it doesn't need the dowel because it is so lightweight.
You don't put buttercream on the styrofoam before fondant. You can brush the styrofoam with water, piping gel or thin royal icing. I prefer the latter 2.

thank you so much

Don't try to do it without putting something (I used piping gel) on the dummies... you end up getting a lot of tears in your fondant... at least I did...

I just rub my wet hands all over the dummy cake before I cover, then the fondant sticks to it perfectly....don't drench it wet, damp is the key word.