tuff e nuff

Hello there yes I'm new to the forum ,and I am clue less I just bought a 2006 ford explorer and it has a pioneer Avicx930 brand it works great but I had to put a new battery on it .and have not had a radio since it says enter password I don't have the password and appears no one else does either .can someone plz help me out. Its to quiet in here.thank you for any info you might have to help !!!