For step8-20, i tried import the list provided but keep showing up 10 Records failed and error massage INVALID_FIELD:Foreign key external ID: P-000 not found for field Name in entity Maxz__Pitch__c:--
Sorry you're stuck but there's almost always a pretty easy fix! Do NOT try to start all over again, uninstall Max's Pitch Package, etc. That can make it worse. There's a 95% chance the same snag/fix is listed & answered in the Help FAQ. But if you can't find it there, post your problem here.
Make sure you post in the right category below & be sure to include a screencap showing the issue!