The temp control should be hooked up of the under tank heater not the light.
1 you only need the belly heat not back hear for a BP so jut get rid of the light altogether.
2 I have been told hooking up heat bulbs to a temp controller is bad. The bulbs you most likely are using won't be designed for that. Not all bulbs are controllable.
But really just get to I the lamp and only use the heat mat.
Also you would need a hide for the cool side of the tank as well. For substrate you can use pretty much anything you want (that is a normal substrate) except for cedar or pine shavings. Most people use aspen shavings or even just paper towels for easier clean up.
Also I can't Remeber if you said a water dish or not. You need one of those. BP tanks can be kept bery basic.
2 hides , water dish, substrate, under tank heater, temp controler of some sort (thermostat, rheostat) and thermometer with probe(unless the thermostat has one). That's basically all you need for the tank