HELLO

question. Do I need to back up my wallet from time to time and put it into a USB?
and what does save keys do? I don't remember having a private key only a password on the wallet
thanks
Yes, you need to backup the file (at least once).
The private key is somehow encoded in the wallet file and there's no direct way to extract it with the provided software. There is also no way to restore a wallet with a key or seed words (something that will be addressed by the recent announcement of switching ITNS to a monero based code)