Setup a password. But now when entering the password it says wrong password

I just bought a MacBook Air 11 inch, mid 2013 edition. When I started my MBA to go through the initial setup assistant, the voice over feature was on. So I learned how to go through with that but I was just entering my time zone when I got bored and put my MBA in sleep mode. When I opened it it asked me for my password. When I enter the password, it keeps saying it is wrong password. I think I was by able to finish the whole setup assistant also. I am very new to Mac. I have no idea how things are done.