no
There is no way to update your iPod from your iPod. You have to do it on iTunes on your computer.
No.
Plug in your iPod and start up iTunes. Click on your iPod as it appears on the list, then go to the settings/management tab (I'm sorry, I'm not sure of it's exact name.) Then, if possible, click on...
Plug it into a computer, open iTunes, goto your iPod, pick update firmware, wait for it to download, it will install automatically