Wireless networking with fiber internet connection

My ISP is BellSouth (Now known AT&T). I do not use a modem to connect to the internet. I believe the type of service I have is called “fiber”. I have been trying to create a wireless network in my home but I have not been successfull. I have tried brands such as Belkin, Netgear, D-Link and Linksys. Do I have to configure the router to accept my internet connection? If so, how do I do this?