There are several things to consider.
First, you want to ensure your PC and monitors are physically connected to each other.  It is common to use a combination of DisplayPort HDMI and VGA connections.  Recently, the market has expanded its use of USB-C and Thunderbolt Technology.  It then becomes possible to connect monitors with a combination of DisplayPort, HDMI, USB-C, and Thunderbolt cables.  You’ll also want to determine if you intend to daisy chain 2 monitors together or instead connect 2 monitors individually to connections on the PC.  Daisy chaining is when you connect one monitor to the PC directly and then the second monitor is only connected to the first monitor.  Some PCs such as Macs can support 2 monitors, but only with full capability in the non-daisy chain scenario.
In non-daisy chaining scenarios, you’ll need to ensure your GPU can drive to separate displays.  As monitors advance in resolution and capabilities, it also becomes important to consider the data bandwidth required of the CPU and cables.  For this type of detailed information, it is best to read through the manufacturers guidelines to ensure your PC can support all the requirements for 2 monitors.