There is a good rule of thumb for covid-distancing:
Imagine the person you are near was smoking a cigarette; would you be able to smell it ?
-- If so, then if that person had the virus, it would likely infect you. As for the spread of smoke particles, so for virus particles.
If you think like this, you will keep as distant as possible from others. If possible, at least two metres, or even more. In supermarkets etc., do your best.
... And always remember it could be you with the virus, all unknown. You do not want to infect anyone possibly a vulnerable person with a possibly fatal disease just by careless proximity. Do you?