I am pretty new at all of this and have never made any figures. I am making a fall-themed baby shower cake and thought it would be cute to put a baby in a fall leaf and maybe hiding behind some pumpkins. Can anyone tell me how to make baby figures and what to make them out of? I have never worked with gumpaste - what's the difference between that and fondant?

gumpaste dries harder and faster than fondant.

You might try a clay modeling book for an example of the baby figure. the techniques would be the same.

I find rolled buttercream easy to mold and easy to color.
It sounds like an adorable idea!

Aine2 is a great resource for modelling. She has some tutorials for sale (I think they are $8 or so, but from what I have heard they are worth every penny) on her website and one of them is how to sculpt a baby (I almost wrote "how to make a baby" but I guess that would be a whole different website LOL). Anyway...here is the link if you want to check it out:

http://www.lorraine-icingonthecake.co.uk/masterclasses/masterclass.htm