Where do I find the underpayment penalty on my federal and ca state and how do I pay the amount due?

Your federal underpayment penalty, computed on Form 2210, is shown on line 38 of Form 1040. 

Your California penalty, calculated on Form 5805 or, less commonly, Form 5805F for Farmers and Fishermen, is shown on line 113 of Form 540.

They are both paid with their respective returns when you file.

thank you for the information,  the state i found but on the federal there was nothing on line 38 of the federal form and no form 2210.   at some  point i saw a penalty of $45 and now i don't find it anyway so not sure if i should send in 45 or just move on supposing it has been taken care of in some manner.

It may have resolved itself if you are no longer subject to the underpayment penalty.  

You can also review your input and review this section by following the instructions in the link below.

Underpayment penalties