By providing this information, it is possible to get an answer faster then having to ask a lot of questions like the ones below...
Is your power supply wattage enough to run a RX 580?
Is your monitor plugged into the GPU and not the motherboard?
Is the PCIe slot enabled in the BIOS?
Are you using any kind of adaptor cable?
Is your computer a prebuilt system? Will the motherboard / BIOS allow you to use the new GPU?
What GPU were you using before?
Used on Amazon??? UG. A lot of these were used for Mining (which drove up the prices) and could be burnt toast.