Can't get pass administration password

I bought a Inspiron 14 Dell laptop from goodwill and when I try to turn it on, the screen pops up needing a administration password which I do not know and have no way to find out. Plus the screen will not go to anything else and will shut off after I try to punch in passwords that I have looked up searching. Please can someone help me because I am at a lost of what to do next. On the screen it says, " Please type in the system or administrator password and press <enter>.