Face covering is an added layer of protection. Asymptomatic people can have the virus and inadvertently pass it along to others. A mask is not a virus-blocking solution that will allow you to return to normal social interactions.  

According to the CDC, a well-made mask that is snugly secured around the ears is best. Alternatively, any type of face covering like a bandanna or scarf is better than nothing if you must go out, although the CDC cautions that these are not considered proper protective gear and should only be used as a last resort. In either case, you want to be sure your nose and mouth are securely covered from all sides so droplets can't escape.