How can i log in to my new mac?

I just got a new macbook pro and followed through all the steps to transfer things to my pc. Now when it started up it gives me 2 options to click. TMartineZ, which was my account name from my pc. And then theres ASP.NET Machine Account. After clicking either it has me enter a password but it also says password expired click to change. However i never set a password and therefore dont have the old password and cant use my new mac. I tried using the password from my pc and my itunes account with no success. Help me please.