Complex sentence: Allsup's is a 24 hour chain, which sells fuel under the Shell, Fina, ConocoPhillips, Exxon and Allsup's On the Go brands, as well as traditional convenience store items and prepared food items like burritos and barbecue beef sandwiches.
Split into simpler sentences: Allsup's is a 24 hour chain that sells fuel under the Shell, FINA, ConocoPhillips, Exxon and Allsup's On the Go brands. It also sells traditional convenience store items and prepared food items including burritos and barbecue beef sandwiches.