Some iCloud data isn't syncing

Clicking System Settings brings up the greyed message "Some Cloud data isn't syncing". I have only unwrapped my new MacBook Air today and this msg is thoroughly frustrating. I do not know what to do to get rid of it. I cannot proceed with using my Mac until I resolve this issue. The msg continues........."It includes saved passwords and data from Health and Maps. Verify your account information to resume syncing."

I hope it is clear to somebody what I need to do because I am not enjoying the Mac experience one little bit at the moment. I will be very grateful if somebody can guide me. Many thanks. John