The light that goes on the license plate on my 91 toyota previa, I need to know where the fuse panel is for that light

It's the same fuse that runs your tail lights. If the plate light isn't working, you probably have a broken wire near the back, or a faulty bulb. Get a wire circuit tester and locate the wire. Check for power at the bulb socket, and if no power, keep making your way back on the wire until you find power, or a broken wire.