I just bought a 3040 800 watt cnc. What electronics do i need to buy to run it?

If you do not have electronics for your CNC, you will need stepper motors (or servos) that will fit your torque requirements, drivers for the motors, a power supply, applicable wires, and an interface board for computer communication. We sell electronic combo kits here https://buildyourcnc.com/electronicscombo.aspx