|Have you got a manual with your router/modem?|
Have you read the manual?
You should be able to connect to the router by lan cable.
Then open your favorite web browser and type in the ip address of the router.
You have to configure the router with the correct authentication data, if required.
Your provider should have send you the data, tneeded to authenticate with your ISP.
Click Here on HowTo ask good Question to get best Help
Let us know, if the problem is solved !!!