The single most important action we can all take, in fighting coronavirus, is to stay at home in order to protect the NHS and save lives.
Full guidance on staying at home and away from others can be found on gov.uk
You should only leave the house for one of four reasons, and one of these is to provide care or to help a vulnerable person. Even when you are doing this, you need to do so safely. You should be minimising time spent outside of the home and ensuring you are 2 metres (6 feet) apart from anyone outside of your household.
This guidance outlines how you can help and importantly, how to do this safely.