Setting up Raspberry Pi Zero
The Raspberry Pi is a low-cost board dedicated to purpose projects. Here, we will use a Raspberry Pi Zero board. Take a look at the following link: https://www.raspberrypi.org/downloads/raspbian/

Testing and accessing the serial COM interface
Once the driver is installed, we have here the Port COM, which is already installed:
Tip
This configuration is for Windows installation; if you have different operating system, you need to do different steps.
How get the Device Manager screen: On your windows PC, click on the Start icon, go to Control Panel, select System, and then click on Device Manager.
In the following screenshot, you can see the device manager of the USB serial port:

pi, and the password is raspberry: