From my understanding, the CMC (converted mana cost) of a token is 0. When you sacrifice a creature with Birthing Pod it adds 1 to the CMC. So, if I sacrifice a token (any token) to Birthing Pod, can I get a creature with a CMC of 1 from my deck?
You are correct in the general sense. The CMC of almost any tokens is 0. The only exception is tokens copying other cards (e.g. Cackling Counterpart).
The simplest reference is the Oracle rulings:
So, why do most tokens have CMC 0?
Normally, in Magic, the absence of a value isn't the same as "zero", but the definition of converted mana cost explicitly covers this situation: