We hope to see you online soon!
People use software for it, there's a variety of ways.
The easiest way, without external programs, is to hit the Prt Sc button on your keyboard, print screen, and paste it in Paint or some kind of image editor and crop it from there.
If you want a simple program, I suggest
ShareX - The best free and open source screenshot tool for Windows
ShareX is a free and open source program that lets you capture or record any area of your screen and share it with a single press of a key. It also allows uploading images, text or other types of files to many supported destinations you can choose from.getsharex.com
I use it and it's fairly simple to set up, and has the ability to make key-binds to take screenshots with and you can crop them from there and even have it automatically upload to Imgur and be saved to your clipboard to send to people. There are videos on YouTube to walk you through on how to do it.
We hope to see you online soon!