It isn't clear what you mean by "the different channel lineup" -- could you describe you are looking for? Perhaps they have it online at https://www.xfinity.com/learn/channel-lineup, or they may have included it with one of your recent bills. Check your billing history at https://customer.xfinity.com/.
Service Centers and Xfinity Stores should have printed channel lineups. Check locations and hours at http://www.xfinity.com/support/service-center-locations/ to pick one up, or call Customer Service at 1-800-Comcast and have them send a lineup to you.