How to use Toshiba laptop with Dell external monitor?

I have a Toshiba Satellite p15 s470, and I am trying to hook it up to an external monitor I have from an old pc, which is a Dell. Can someone walk me through hooking this up? Will it work? Ive plugged everything together but when I push the "monitor" button on the monitor it says "In Power Save Mode - Press any key or move the mouse". Any suggestions?How to use Toshiba laptop with Dell external monitor?Is your laptops external monitor port compatible with dell's monitor's cable ? If it is, power on the computer and external monitor, then press Fn and the Key that has the monitor symbol . ( usually F5 or F10 or any key that has a symbol of a monitor.