The World Health Organization has issued advice to the public here. In addition to regular hand washing it's important to maintain social distancing, specifically maintain at least 1 metre (3 feet) distance between yourself and anyone who is coughing or sneezing.
Why? When someone coughs or sneezes they spray small liquid droplets from their nose or mouth which may contain virus. If you are too close, you can breathe in the droplets, including the COVID-19 virus if the person coughing has the disease.