Can any iPod touch/iPhone model upgrade to iOS5 and beyond?

First, let me apologize if it is a stupid question but I really don't know much about Apple devices.

Anyway, the reason I wanted to know is because I have an iPod touch, I don't know what model it is but I do want to upgrade to iOS5.

Is it possible to upgrade?

Yes you can upgrade to the firmware on your iPod the latest one is iOS6 so you can only upgrade to 6 not 5 just plug it in your computer and itune should pop up and you can upgrade it

If it is jailbroken you can't upgrade it unless you rest it or else your ipod will mess up

No, not just any model will let you upgrade your iOS. For instance the first generation and second generation iPod Touches can't upgrade to iOS5. They are too old and their models can't handle it. I think it tells you what generation iPod Touch you have right on the back of the iPod/iPhone itself. Knowing the generation your iPod is important so you should definitely find out.

Not all.

The
iPhone 3GS, 4, 4S can. The 5 of course came with iOS 6.
iPod touch 3G, 4G can. The 5G came with iOS 6.

The rest, can't.