Recognising my iPod on my iTunes and transfering playlists

I have two parts to my question:

Lenovo PC ideapad Y700-17ISK

iPod model MD480ZP

1. My old PC died (due to complete power loss) and therefore I was unable to get anything transferred from my old PC to my new PC. Luckily, I had my iTunes library saved to an external hard drive. I have installed iTunes onto my new PC and have imported my iTunes library to iTunes under my existing Apple ID account, but when I now link my iPod to my PC and iTunes it makes the statement that everything will be cleared off my iPod if I want to sync my iPod to my PC. Why?
2. I have a playlist of 1874 songs on my iPod which does not seem to be saved in my iTunes library. How do I transfer my playlist from my iPod to my PC.