If your router came with an ethernet cable, connect it to your laptop and the router. On the laptop, press the Wiondows key and R together then in the Run box, type
cmd /k ipconfig /all
and hit Enter.
A black Cmmand form shows up and the information you need is shown under Default Gateway. It will look like 192.168.0.1.
Open Internet Explorer or any other browser and put those numbers in the URL bar as though it was an Internet address. That connects you with the router but you need to log in with a username and password. Often it will be admin for the name and password for the password but it may be printed on the case.
If you get in, look for the wireless security key.