By now, there are thousands of articles, advice columns, blogs, statements, journals and so on about how to protect yourself from COVID 19 (assuming you believe it is a big deal!).
This chart, however, I think best captures the steps you should take. It was designed by Ian M MacKay, a virologist. I discovered it when one of my fav writers, Zeynep Tufekci, used it on her blog (https://lnkd.in/d6dSk4p).
Check out the high res version on Ian’s figshare.