HI
First just prove that you can "see" the router from your laptop.
(with your yellow cable connected to both router and laptop)
Depending upon manufacturer, and model, of router, the most common (IP) addresses you could try....
192.168.1.1
192.168.1.2
192.168.2.1
in the url box, centre-top of your browser window, (you shouldn't need http:// prefix)
if you then "find" the router on one of thos addresses you will almost definitely be presented with a box asking for username/password. The username/password details together with the connection IP address will definitely be in the documentation you received in the box with your new b/band router.
Very common username and password is "admin" and "admin"
Ray