How to clean your Apple products - Apple Support explains:
"Learn how to clean your Mac notebook computer.
MacBook, MacBook Pro, and MacBook Air
When cleaning the outside of your MacBook, MacBook Pro, or MacBook Air, first shut down your computer and unplug the power adapter. Then use a damp, soft, lint-free cloth to clean the computer's exterior. Avoid getting moisture in any openings. Do not spray liquid directly on the computer. Don't use aerosol sprays, solvents, abrasives, or cleaners containing hydrogen peroxide that might damage the finish.
To clean the screen on your MacBook, MacBook Pro, or MacBook Air, first shut down the computer and unplug the power adapter. Dampen a soft, lint-free cloth with water only, then use it to clean the computer's screen.
MacBook Pro models from 2016 and later with Touch Bar and Touch ID: Clean the Touch Bar and Touch ID (power button) on these computers the same way you would clean the display. Shut down your Mac and unplug the power adapter. Dampen a soft, lint-free cloth with water only, then use it to clean the Touch Bar and Touch ID.
MacBook (13-inch, Late 2009) and MacBook (13-inch, Mid 2010): The bottom case of these computers uses a soft nonslip material. Use a 3M Gray Microfiber or soft dye-free, lint-free cloth to clean the bottom case."