Can you tell me what prosesor should be in this

Can you post the model number of the motherboard. It should be between the PCI slots or somewhere around there.
Semprom sda2400 uses Socket A so any CPU that is designed for Socket A will work.
That would be Most of the AMD Semprom family CPUs as well as AMD Athlon XP CPUs
If the on-board graphics card is not working can you check if you have PCI or AGP graphics installed? Usually a AGP and PCI graphics card will disabled on-board graphics card.