I am assuming you didn't purchase your computer with discrete graphic card so you only have video ports on the motherboard. One HDMI and VGA,    You can connect 1 monitor using HDMI to DP (Active) cable. Regular cables will not work you will need an active cable like this one.   Unfortunately connecting second monitor would be a hassle, VGA can not supply enough bandwidth for a DP capable monitor to run.    I would suggest investing in a graphic card. This one can run triple display  Here's a video of the process.  [URL]    
I need some advise how to connect two U2415 monitors to my PC model Inspiron 3880. I can use one HDMI cable to connect one U2415 monitor. I tried VGA adaptor to convert to DP and use DP-in port, but not working. I did some research online and someone said that convert analog signal to digital signal needs special adaptor. Can someone tell me the model number of the adaptor? Other than using adaptor, is there other easy approach to connect dual monitors to my PC? I have a cable that one side is HDMI and the other side is DP. I tried to use this cable to connect one of my monitors (HDMI goes to PC and DP goes to DP-in), but the monitor doesn't receive any signal (I chose DP as the source). I updated the latest graphic updates to my PC (Intel-UHD-Graphics-Driver_PGGJR_WIN_27.20.100.9664_A00_02), but still not work. I know the cable works well with my laptop dock. Any suggestion why DP not work using HDMI/DP cable? Thanks in advance for any thoughts.
Inspiron 3880 connect two U2415 monitors