Dual monitor setup

[Soumyadeep Chatterjee]

I have this old Dell Laptop with i3 4th gen and geforce 820m running updated linux lite with open source drivers and I have one monitor laying around so thought to connect them as the laptop's screen is in pretty bad shape so bought one hdmi to vga cable expecting it to be a plug and play kinda thing but i was wrong as when i connected the external device was just showing cable not detected.

Help needed to connect them and to learn the how to as well.