If your gpu only has one port then no, you cannot run a dual monitor setup (at least with a conventional setup). You could mirror the feed from your main monitor on your secondary monitor but you could not have the two monitors displaying separate things.
Clarification: The above stands true for HDMI, however with dp 1.2 you can run two monitors from one port.
Make and model of your graphics card? Make and model of your monitors? Better yet, list your specs to your build like so:
CPU:
Motherboard:
Ram:
SSD/HDD:
GPU:
PSU:
Chassis:
OS:
include the age of the PSU and the version for your OS is you're on Windows 10.
If your gpu only has one port then no, you cannot run a dual monitor setup (at least with a conventional setup). You could mirror the feed from your main monitor on your secondary monitor but you could not have the two monitors displaying separate things.
Clarification: The above stands true for HDMI, however with dp 1.2 you can run two monitors from one port.