iPod won’t connect toiTunes
My 4th Gen iPod will not connect to iTunes or App Store
To access the Store from an iPod Touch requires iOS 10.0 or later, but a 4th gen iPod Touch will almost certainly be using iOS 6.1.6 (it cannot go higher than that).
You can manage the iPod from iTunes on a PC or Mac, or on newer Mac, Finder. If iTunes on a computer doesn't recognise your iPod, strat with this Apple article: If your computer doesn’t recognise your iPhone or iPad – Apple Support (UK)