You mentioned you will be researching PARES.  It’s a very interesting site, but I’ve never found how to confirm that the info you find for the name entered in the search, is the person you need; es

You mentioned you will be researching PARES.  It’s a very interesting site, but I’ve never found how to confirm that the info you find for the name entered in the search, is the person you need; especially if one’s prior knowledge on the person is limited to name, place of origin (no birth dates), and maybe parents’ names.  Please share your PARES research experience with us. 
I hope you crack the “Spanish code”!  Have you ever tried ascagen.es?  It’s specifically for Cantabrian genealogy. 
Good luck and keep us posted.    Alice