Since you're not being very specific, what have you tried? Hard reset might work, same with trying different charging cables, but if the iPod has been off or dead for a number of years it's likely that the battery might have gone flat. Since Apple no longer repairs these devices since they're obsolete, there's a good chance you might have to disassemble it yourself and have a look. If this is the case, you will need a new battery which will probably be hard to find considering the age of this device. It's an old iPod so it's common that the battery would be dead. This is why you should charge it to 50% and power it down when you're going to store it for a long period of time. Either way, I would replace the battery because like oldturkey said, it's coming to the end of it's lifetime.