2002 GEM will not startHELP

Hello and thank you for letting us join. We have a 2002 GEM car model number E825. We have replace the batteries and cables. We have put in a new. Controller. The car will not start. It was doing great. Once the batteries and cable was replaced. We drove it no problems but now it will not start. Any help is beyond. Greatly appreciate it.

Is the main switch, under the seat, turned to on?

Has it been plugged in to charge?
Do you own a gas can?