To make a screenshot, press the print screen key (I don't know how it's abbreviated in English, maybe PrntScrn or similar) on your keyboard. Then open Paint and paste it there
Yes at devansh_asthana was saying the typing keys is ctrl+Alt+PrtScn All at the same time=Screen saved. then you can put in Microsoft, paint, or pages and crop.
I recommend downloading the program LightShot. Ever since I got it screenshotting is much quicker and you can get exactly what you want right away, no cropping required.