Do Honey and cinnamon prevent pimples?

I'm not aware of any evidence that honey and cinnamon prevents acne.

There is, however, a body of respected research that raw (unheated, untreated) honey itself has antibacterial, antibiotic and anti-inflammatory properties, and these are bound to help with at least some aspects of acne. Do NOT apply cinnamon to your face!!! It has a bad reaction on your face. It will turn your face RED bright RED. I tried it, trust me.