In future a little more information would be useful - like router brand - model etc...
I am guessing that you have a netgear router - the default username is "admin" the default password is "password"
Here is a link to their manual
If you have connected everything up correctly (refer manual) then entering www.routerlogin.net into your internet browser should take you to the login screen.
use the username/password I gave you.
If it doesn't work - (it's had the username/password changed) then factory reset it (refer the manual.)