The main screen of the router should show your status. If it says DSL connected but internet NOT CONNECTED it means there is a problem with the userid and password.
If both are connected then you have a problem on the lan side of things. Too many options to even guess which is wrong but pretty much it is start with a wired connection and see if you get a ip and can ping the router. Mostly its go back to the manual and follow the setup procedure to find what you missed.