Can I upgrade my iPod iOS to latest?

Hi Apple Family,

I have an iPod with iOS version 3.1.3. If I want to download any Apps, it says it is not compatible due to 3.1.3. Hence I wanted to upgrade my iOS to latest. Can anyone please guide me as to is the upgrade possible and if yes how to upgrade please? I have checked and found that my iPod is of older generation, doesn't have camera, looks like I have first generation iPod. Please advice. Thanks in advance. Cheers!

Regards