Turning on a flashlight uses a battery, right? Chemical energy is stored in that battery. If you use the battery, you're converting that chemical energy to an electrical energy.
In a flashlight then, the electrical energy becomes light energy and thermal energy in the bulb. Why light and thermal? The flashlight gives us light and then, gives out heat. This is why when we touch light bulbs, it feels hot.
I hope you find this answer the most helpful! :)