Cannot connect dual monitor HP Pavilion 590-p0041cb

[bell2021]

I purchased an additional HP monitor (27 fw with audio) and have tried numerous times to connect it to my HP Pavilion 590-p0041cb as a dual monitor. The desktop only has one HDMI port so I purchased an adapter to use on the VGA (I believe) port that is directly beneath the HDMI port. When I do so, the monitors don't respond properly - one is black while the other is modified (desktop icons disappear). I right click to bring up the display settings. On the bottom of the toolbar, it shows that it's open, but no matter how many times I click on it, it doesn't come up. I've tried swapping monitor connections thinking that it's displayed on the black monitor but that doesn't solve it, either. Essentially, my computer doesn't work as long as I have the other cable connect. 

Please help. I want so badly to be able to use dual monitors. 

[banhien]

@bell2021 

Its specs

        https://support.hp.com/in-en/document/c06185420

Its motherboard has following ports at its back

• Audio Line-in
• Speakers
• Microphone jack
• HDMI
• VGA
• LAN (Ethernet)
• USB 2.0
• USB 3.1

You should be able to connect 2 monitor to it, one HDMI and one VGA (no conversion).

Regards.