How far do you have to stay from the person next to you so not to catch corona virus or the flu from them? is it 3 feet? i've also heard 6 feet.

Not yet known: The details of person-to-person transmission of the novel coronavirus (nCoV) are not yet known. Press reports indicate some infected persons may be "super transmitters"; just being in the same room might be risky.

COVID 19: It is recommended that you maintain at least 6 foot distance and wear a mask if in presence of people outside of those whom you live with. However, a really vigorous cough and sneeze - can send droplets out to 9 feet.