I have a Verizon note 8 and I'm trying to my put metro Pcs sim card and it doesn't work .. does the note 8 for Verizon have to be fully paid off or what ?
The Verizon Note8 has both CDMA and GSM radios, so it still ought to work. Verizon phones have historically been carrier unlocked in recent years, although I believe they're going to start carrier-locking them again soon -- not sure if that's happened yet.
Try going into the network settings and change Network Mode to LTE/GSM/UMTS.