How to set up a slave flash on a nikon D5000?

I found a new/old slave flash in my garage and water to use it for my nikon d5000 but it doesn't seem to work do i have to go into the setting or something? It works with the camera that it came with

Added (1). It came with a sharp vision camera its a basic flash it works if i have the flash down and then have it repopup and it will fire before i fully press the shutter button

Make and model of flash? What camera did it come with? How are you attempting to use it as a slave?

It will probably work, but since your D5000 has no internal controller for off-camera flash, you will need to turn on the optical slave of the flash itself, add an optical trigger to the flash, or get radio frequency flash triggers.

Without knowing what you have, not much else I can help you with.

I bought a Yongnuo flash speedlite yn460 digital auto flash how do I set it up to be the slave? To be used on a D5000 Nikon dts