Can I Birthing Pod a token to get a creature with a CMC of 1?
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:


  6/1/2011  A token has a converted mana cost of 0, unless it is copying
  something else.
  
  6/1/2011  If a creature is copying something else, its converted mana
  cost is the converted mana cost of whatever it's copying.




So, why do most tokens have CMC 0?


  110.5b ... A token doesn't have any characteristics not defined by the spell or ability that created it.
  
  Example: Jade Mage has the ability "{2}{G}: Put a 1/1 green Saproling
  creature token onto the battlefield." The resultning token has no mana
  cost, supertype, expansion symbol, rules text, or abilities.


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:


  202.3a The converted mana cost of an object with no mana cost is 0.