1994 Toyota Camery

I'll need a little more information. I'm assuming your engine is overheating when the radiator overflows.

You'll need to first check the belt around the water pump. Then make sure the fans are coming on when the engine reaches operating temp.

Next check that the thermostat isn't stuck closed by feeling bother hoses after engine reaches temp. If one is hot, the other isn't, then the thermostat is stuck. Replace it.

Next you can verify the pump is pumping by squeezing the upper hose while someone presses gas. You'll feel the pressure building as engine speed increases.

Then you want to flush the system, making sure there's no blockages (or leaks).