keyboard not responding

Hi! I'm a complete novice when it comes to PC building, but thought I'd try and revamp my family's old 2012 PC by installing a new GPU. It's an HP Pavilion p7-1167c Desktop PC with Core i5 2400 Processor 300 W PSU (new) GeForce GTX 1650 GPU (built in) Intel HD Graphics 2000 Windows 7...