whom should I call to defend outstanding false Identity theft warrant on me i just found out?

If you can come up with the money, I recommend you consult with a local attorney immediately.  Since a warrant for your arrest already has been issued, you may get arrested at any time -- and may want to talk to the attorney about turning yourself in and making advance arrangments to get bonded out right away.  Many persons who are charged or arrested believe if they are innocent they don't have to seek representation because they can explain to law enforcement that they're innocent.  It doesn't work that way.  That's the purpose of a trial.  But you need personal legal advice now.  You have a right to remain silent regardless of whether you're in, or not in, custody -- and even if law enforcement doesn't tell you that.  Again, I've had many clients who, before consulting with me, thought if they were innocent, they had no reason to remain silent.  That is WRONG!  So the best advice I can give is to exercise your right to remain silent until after you've consulted with your attorney, one-on-one.  That attorney should be able to help you understand how to proceed and whether you should continue to remain silent.