an easier idea. rip apart a cheap, working flashlight, and discover how it works.
i need to build something not destroy something
Sometimes, destroying items teaches you how to build items. Ever thought about it?
and more often than not, some destroyed items contain valuable parts which canbe desoldered and reused for free. A heck of a lot cheaper than buying from an electronics store.
The only other suggestion is to buy a flashlight bulb, buy a battery, and connect the metal bulb point to one battery terminal, and connect the side to the other battery terminal with a wire, and it will light.
You will discover the easiest part of conductivity.