Press the Windows logo button + Volume Down button at the same time
Use the Snipping Tool from the Start menu
Press Print Screen if your Surface keyboard has that key
Press Alt + Print Screen to capture the active window
Press Windows logo key + Shift + S to open Snip & Sketch
Use the Power button + Volume Up button on some Surface models
Find saved screenshots in the Pictures > Screenshots folder
Paste the screenshot into Paint or another app with Ctrl + V