Can I take a screenshot on a desktop Apple?

Yes.

Press the cmnd+shift+5 keys on your keyboard to capture the entire screen.

cmnd+shift+3 to capture all screens.

cmnd+shift+4 to select an area.

Details here: How to take a screenshot on your Mac - Apple Support

You can take a screen shot of the entire Desktop, an open application window, or interactively drag a box around anything on your Desktop (e.g. icon) to capture it into a file that is written to your Desktop. In System Preferences : Keyboard : Shortcuts : Screenshots, here are your capture choices:

The last choice is Mojave or later only.

Use the Windows key as the cmnd key.