Child born in California but lives in Nevada

These days, the place of testing could be remote from where any person lives (drug stores, these days, have lots of "do-it-yourself" kits for all kinds of testing, but I don't think they've added paternity yet).  You appear to be asking where to file an action to determine paternity.  Your facts are a bit sketchy to answer definitively, as generally the place of conception is proper, as is the place where "the child, the mother, or the alleged father resides or is found," and the action can be joined with one for divorce, annulment, separate maintenance, or support.  See http://willicklawgroup.com/paternity/.