Hi
I can see that you are trying to fix your iPod (my favourite thing to fix) and here’s some answers
The screen is a 6th gen screen so don’t buy it because it won’t work.I would try eBay for a 5th gen screen
If you can show me a photo of what part of the connector is on the board and what part has fallen off I can help you with that
And last but not least the max ammount of storage a 5/5.5gen iPod classic can take is 1TB but the amount of songs that is on it can change that
Hopefully this answers your question
Thanks :)